WiFi multi-band communication

ABSTRACT

A method for wireless local area network (WLAN) communication by a first WLAN communication device is described. A first media access control (MAC) data unit is generated at the first WLAN communication device. The first MAC data unit is transmitted from the first WLAN communication device to a second WLAN communication device via a first WLAN communication channel having a first radio frequency (RF) bandwidth. A second MAC data unit is received at the first WLAN communication device from the second WLAN communication device via a second WLAN communication channel having a second RF bandwidth that does not overlap the first RF bandwidth. The second MAC data unit corresponds to an acknowledgment of the first MAC data unit from the second WLAN communication device.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/791,519, entitled “Frequency Division Duplex (FDD)Over Channel Aggregation” and filed on Jan. 11, 2019, which is herebyincorporated herein by reference in its entirety.

This application is related to U.S. patent application Ser. No.16/162,113, entitled “WiFi Channel Aggregation” and filed on Oct. 16,2018, which is hereby incorporated by reference in its entirety.

FIELD OF TECHNOLOGY

The present disclosure relates generally to wireless communicationsystems, and more particularly to data transmission and reception overmultiple communication channels.

BACKGROUND

Wireless local area networks (WLANs) have evolved rapidly over the pasttwo decades, and development of WLAN standards such as the Institute forElectrical and Electronics Engineers (IEEE) 802.11 Standard family hasimproved single-user peak data throughput. For example, the IEEE 802.11bStandard specifies a single-user peak throughput of 11 megabits persecond (Mbps), the IEEE 802.11 a and 802.11 g Standards specify asingle-user peak throughput of 54 Mbps, the IEEE 802.11 n Standardspecifies a single-user peak throughput of 600 Mbps, and the IEEE 802.11ac Standard specifies a single-user peak throughput in the gigabits persecond (Gbps) range. The IEEE 802.11 ax Standard now under developmentsignificantly improves throughput over the IEEE 802.11 ac Standard.

SUMMARY

In an embodiment, a method for wireless local area network (WLAN)communication by a first WLAN communication device includes generating,at the first WLAN communication device, a first media access control(MAC) data unit. The method also includes transmitting, from the firstWLAN communication device, the first MAC data unit to a second WLANcommunication device via a first WLAN communication channel having afirst radio frequency (RF) bandwidth. The method further includesreceiving, at the first WLAN communication device, a second MAC dataunit from the second WLAN communication device via a second WLANcommunication channel having a second RF bandwidth that does not overlapthe first RF bandwidth, wherein the second MAC data unit corresponds toan acknowledgment of the first MAC data unit from the second WLANcommunication device.

In another embodiment, a method for WLAN communication by a first WLANcommunication device includes receiving, at the first WLAN communicationdevice, a first media access control (MAC) data unit from a second WLANcommunication device via a first WLAN communication channel having afirst radio frequency (RF) bandwidth. The method also includesgenerating, at the first WLAN communication device, a second MAC dataunit configured to acknowledge the first MAC data unit. The methodfurther includes transmitting, by the first WLAN communication device,the second MAC data unit to the second WLAN communication device via asecond WLAN communication channel having a second RF bandwidth that doesnot overlap the first RF bandwidth.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example wireless local area network(WLAN), according to an embodiment.

FIG. 2A is a block diagram of an example physical layer (PHY) data unit,according to an embodiment.

FIG. 2B is a block diagram of an example preamble of a PHY data unit,according to an embodiment.

FIG. 3 is a block diagram of an example system architecture configuredfor multi-channel communication, according to an embodiment.

FIG. 4A is a diagram of an example system architecture corresponding toa communication device configured for multi-channel operation, accordingto an embodiment.

FIG. 4B is a diagram of another example system architecturecorresponding to a communication device configured for multi-channeloperation, according to another embodiment.

FIG. 5 is a diagram of an example signal transmission sequence overaggregated communication channels, according to an embodiment.

FIG. 6 is a diagram of an example signal transmission sequence overaggregated communication channels using frequency division duplexing,according to an embodiment.

FIG. 7 is a diagram of another example signal transmission overaggregated communication channels using frequency division duplexing,according to another embodiment.

FIG. 8A is a diagram of an example channelization scheme correspondingto multiple channels, according to an embodiment.

FIG. 8B is a diagram of another example channelization schemecorresponding to multiple channels, according to another embodiment.

FIG. 9 is a diagram of another example system architecture correspondingto a communication device configured for multi-channel operation,according to another embodiment.

FIG. 10 is a flow diagram of an example method for wireless local areanetwork (WLAN) communication, according to an embodiment.

FIG. 11 is a flow diagram of another example method for WLANcommunication, according to an embodiment.

DETAILED DESCRIPTION

The Federal Communication Commission (FCC) now permits wireless localarea networks (WLANs) to operate in multiple radio frequency (RF) bands,e.g., the 2.4 GHz band (approximately 2.4 to 2.5 GHz), and the 5 GHzband (approximately 5.170 to 5.835 GHz). Recently, the FCC proposed thatWLANs can also operate in the 6 GHz band (5.925 to 7.125 GHz). CurrentIEEE 802.11 Standard protocols only permit a WLAN to operate in one RFband at a time. For example, the IEEE 802.11n Standard protocol isdefined only for operation in the 2.4 GHz band, whereas the IEEE802.11ac Standard protocol is defined only for operation in the 5 GHzband. The IEEE 802.11ax Standard protocol, now under development, willpermit a WLAN to operate in the 2.4 GHz band or the 5 GHz band, but notboth the 2.4 GHz band and the 5 GHz band at the same time.

A future WLAN protocol, now under development, may permit multi-bandoperation in which a WLAN can use spectrum in multiple RF bands at thesame time. For example, the future WLAN protocol may permit aggregationof spectrum in a first RF band with spectrum in a second RF band to forma composite communication channel that can be used to transmit packetsthat span the composite communication channel. As another example, thefuture WLAN protocol may employ frequency division duplex (FDD)techniques in which a first communication channel in a first RF band isused for one type of communications (e.g., downlink data transmissions,or data communications) and a second communication channel in a secondRF band is used for another type of communications (e.g., uplink datatransmissions, or acknowledgments of the data communications). In somescenarios, FDD techniques provide duplexing gain by allowing traffic intwo directions simultaneously, for example, downlink and uplink traffic,or forward and reverse traffic.

Multi-channel communication techniques described below are discussed inthe context of wireless local area networks (WLANs) that utilizeprotocols the same as or similar to protocols defined by the 802.11Standard from the Institute of Electrical and Electronics Engineers(IEEE) merely for explanatory purposes. In other embodiments, however,multi-channel communication techniques are utilized in other types ofwireless communication systems such as personal area networks (PANs),mobile communication networks such as cellular networks, metropolitanarea networks (MANs), satellite communication networks, etc.

FIG. 1 is a block diagram of an example wireless local area network(WLAN) 110, according to an embodiment. The WLAN 110 includes an accesspoint (AP) 114 that comprises a host processor 118 coupled to a networkinterface device 122. The network interface device 122 includes one ormore medium access control (MAC) processors 126 (sometimes referred toherein as “the MAC processor 126” for brevity) and one or more physicallayer (PHY) processors 130 (sometimes referred to herein as “the PHYprocessor 130” for brevity). The PHY processor 130 includes a pluralityof transceivers 134, and the transceivers 134 are coupled to a pluralityof antennas 138. Although three transceivers 134 and three antennas 138are illustrated in FIG. 1, the AP 114 includes other suitable numbers(e.g., 1, 2, 4, 5, etc.) of transceivers 134 and antennas 138 in otherembodiments. In some embodiments, the AP 114 includes a higher number ofantennas 138 than transceivers 134, and antenna switching techniques areutilized.

In an embodiment, the network interface device 122 includes multiple PHYprocessors 130 to facilitate multi-band communication, where respectivePHY processors 130 correspond to respective RF bands. In anotherembodiment, the network interface device 122 includes a single PHYprocessor 130, where each transceiver 134 includes respective RF radioscorresponding to respective RF bands to facilitate multi-bandcommunication.

The network interface device 122 is implemented using one or moreintegrated circuits (ICs) configured to operate as discussed below. Forexample, the MAC processor 126 may be implemented, at least partially,on a first IC, and the PHY processor 130 may be implemented, at leastpartially, on a second IC. As another example, at least a portion of theMAC processor 126 and at least a portion of the PHY processor 130 may beimplemented on a single IC. For instance, the network interface device122 may be implemented using a system on a chip (SoC), where the SoCincludes at least a portion of the MAC processor 126 and at least aportion of the PHY processor 130.

In an embodiment, the host processor 118 includes a processor configuredto execute machine readable instructions stored in a memory device (notshown) such as a random access memory (RAM), a read-only memory (ROM), aflash memory, etc. In an embodiment, the host processor 118 may beimplemented, at least partially, on a first IC, and the network device122 may be implemented, at least partially, on a second IC. As anotherexample, the host processor 118 and at least a portion of the networkinterface device 122 may be implemented on a single IC.

In various embodiments, the MAC processor 126 and/or the PHY processor130 of the AP 114 are configured to generate data units, and processreceived data units, that conform to a WLAN communication protocol suchas a communication protocol conforming to the IEEE 802.11 Standard oranother suitable wireless communication protocol. For example, the MACprocessor 126 may be configured to implement MAC layer functions,including MAC layer functions of the WLAN communication protocol, andthe PHY processor 130 may be configured to implement PHY functions,including PHY functions of the WLAN communication protocol. Forinstance, the MAC processor 126 may be configured to generate MAC layerdata units such as MAC service data units (MSDUs), MAC protocol dataunits (MPDUs), etc., and provide the MAC layer data units to the PHYprocessor 130. The PHY processor 130 may be configured to receive MAClayer data units from the MAC processor 126 and encapsulate the MAClayer data units to generate PHY data units such as PHY protocol dataunits (PPDUs) for transmission via the antennas 138. Similarly, the PHYprocessor 130 may be configured to receive PHY data units that werereceived via the antennas 138, and extract MAC layer data unitsencapsulated within the PHY data units. The PHY processor 130 mayprovide the extracted MAC layer data units to the MAC processor 126,which processes the MAC layer data units.

PHY data units are sometimes referred to herein as “packets”, and MAClayer data units are sometimes referred to herein as “frames”.

In connection with generating one or more radio frequency (RF) signalsfor transmission, the PHY processor 130 is configured to process (whichmay include modulating, filtering, etc.) data corresponding to a PPDU togenerate one or more digital baseband signals, and convert the digitalbaseband signal(s) to one or more analog baseband signals, according toan embodiment. Additionally, the PHY processor 130 is configured toupconvert the one or more analog baseband signals to one or more RFsignals for transmission via the one or more antennas 138.

In connection with receiving one or more signals RF signals, the PHYprocessor 130 is configured to downconvert the one or more RF signals toone or more analog baseband signals, and to convert the one or moreanalog baseband signals to one or more digital baseband signals. The PHYprocessor 130 is further configured to process (which may includedemodulating, filtering, etc.) the one or more digital baseband signalsto generate a PPDU.

The PHY processor 130 includes amplifiers (e.g., a low noise amplifier(LNA), a power amplifier, etc.), a radio frequency (RF) downconverter,an RF upconverter, a plurality of filters, one or more analog-to-digitalconverters (ADCs), one or more digital-to-analog converters (DACs), oneor more discrete Fourier transform (DFT) calculators (e.g., a fastFourier transform (FFT) calculator), one or more inverse discreteFourier transform (IDFT) calculators (e.g., an inverse fast Fouriertransform (IFFT) calculator), one or more modulators, one or moredemodulators, etc.

The PHY processor 130 is configured to generate one or more RF signalsthat are provided to the one or more antennas 138. The PHY processor 130is also configured to receive one or more RF signals from the one ormore antennas 138.

The MAC processor 126 is configured to control the PHY processor 130 togenerate one or more RF signals by, for example, providing one or moreMAC layer data units (e.g., MPDUs) to the PHY processor 130, andoptionally providing one or more control signals to the PHY processor130, according to some embodiments. In an embodiment, the MAC processor126 includes a processor configured to execute machine readableinstructions stored in a memory device (not shown) such as a RAM, a readROM, a flash memory, etc. In another embodiment, the MAC processor 126includes a hardware state machine.

The WLAN 110 includes a plurality of client stations 154. Although threeclient stations 154 are illustrated in FIG. 1, the WLAN 110 includesother suitable numbers (e.g., 1, 2, 4, 5, 6, etc.) of client stations154 in various embodiments. The client station 154-1 includes a hostprocessor 158 coupled to a network interface device 162. The networkinterface device 162 includes one or more MAC processors 166 (sometimesreferred to herein as “the MAC processor 166” for brevity) and one ormore PHY processors 170 (sometimes referred to herein as “the PHYprocessor 170” for brevity). The PHY processor 170 includes a pluralityof transceivers 174, and the transceivers 174 are coupled to a pluralityof antennas 178. Although three transceivers 174 and three antennas 178are illustrated in FIG. 1, the client station 154-1 includes othersuitable numbers (e.g., 1, 2, 4, 5, etc.) of transceivers 174 andantennas 178 in other embodiments. In some embodiments, the clientstation 154-1 includes a higher number of antennas 178 than transceivers174, and antenna switching techniques are utilized.

The network interface device 162 is implemented using one or more ICsconfigured to operate as discussed below. For example, the MAC processor166 may be implemented on at least a first IC, and the PHY processor 170may be implemented on at least a second IC. As another example, at leasta portion of the MAC processor 166 and at least a portion of the PHYprocessor 170 may be implemented on a single IC. For instance, thenetwork interface device 162 may be implemented using an SoC, where theSoC includes at least a portion of the MAC processor 166 and at least aportion of the PHY processor 170.

In an embodiment, the host processor 158 includes a processor configuredto execute machine readable instructions stored in a memory device (notshown) such as a RAM, a ROM, a flash memory, etc. In an embodiment, thehost processor 158 may be implemented, at least partially, on a firstIC, and the network device 162 may be implemented, at least partially,on a second IC. As another example, the host processor 158 and at leasta portion of the network interface device 162 may be implemented on asingle IC.

In various embodiments, the MAC processor 166 and the PHY processor 170of the client device 154-1 are configured to generate data units, andprocess received data units, that conform to the WLAN communicationprotocol or another suitable communication protocol. For example, theMAC processor 166 may be configured to implement MAC layer functions,including MAC layer functions of the WLAN communication protocol, andthe PHY processor 170 may be configured to implement PHY functions,including PHY functions of the WLAN communication protocol. The MACprocessor 166 may be configured to generate MAC layer data units such asMSDUs, MPDUs, etc., and provide the MAC layer data units to the PHYprocessor 170. The PHY processor 170 may be configured to receive MAClayer data units from the MAC processor 166 and encapsulate the MAClayer data units to generate PHY data units such as PPDUs fortransmission via the antennas 178. Similarly, the PHY processor 170 maybe configured to receive PHY data units that were received via theantennas 178, and extract MAC layer data units encapsulated within thePHY data units. The PHY processor 170 may provide the extracted MAClayer data units to the MAC processor 166, which processes the MAC layerdata units.

The PHY processor 170 is configured to downconvert one or more RFsignals received via the one or more antennas 178 to one or morebaseband analog signals, and convert the analog baseband signal(s) toone or more digital baseband signals, according to an embodiment. ThePHY processor 170 is further configured to process the one or moredigital baseband signals to demodulate the one or more digital basebandsignals and to generate a PPDU. The PHY processor 170 includesamplifiers (e.g., an LNA, a power amplifier, etc.), an RF downconverter,an RF upconverter, a plurality of filters, one or more ADCs, one or moreDACs, one or more DFT calculators (e.g., an FFT calculator), one or moreIDFT calculators (e.g., an IFFT calculator), one or more modulators, oneor more demodulators, etc.

The PHY processor 170 is configured to generate one or more RF signalsthat are provided to the one or more antennas 178. The PHY processor 170is also configured to receive one or more RF signals from the one ormore antennas 178.

The MAC processor 166 is configured to control the PHY processor 170 togenerate one or more RF signals by, for example, providing one or moreMAC layer data units (e.g., MPDUs) to the PHY processor 170, andoptionally providing one or more control signals to the PHY processor170, according to some embodiments. In an embodiment, the MAC processor166 includes a processor configured to execute machine readableinstructions stored in a memory device (not shown) such as a RAM, a ROM,a flash memory, etc. In an embodiment, the MAC processor 166 includes ahardware state machine.

In an embodiment, each of the client stations 154-2 and 154-3 has astructure that is the same as or similar to the client station 154-1.Each of the client stations 154-2 and 154-3 has the same or a differentnumber of transceivers and antennas. For example, the client station154-2 and/or the client station 154-3 each have only two transceiversand two antennas (not shown), according to an embodiment.

In various embodiments, the AP 114 is configured to generate an MPDU 180and transmit the MPDU 180 to the client station 154-1 in a first WLANcommunication channel (e.g., channel 608, FIG. 6), and furtherconfigured to receive an acknowledgment 181 from the client station154-1 in a second WLAN communication channel (e.g., channel 616, FIG.6). In an embodiment, the first WLAN communication channel has a firstRF bandwidth and the second WLAN communication channel has a second RFbandwidth that does not overlap the first RF bandwidth. In a furtherembodiment, the first RF bandwidth and the second RF bandwidth areseparated by a gap in frequency and are non-contiguous. In at least somescenarios, communication in the WLAN 110 is improved by receiving theacknowledgment 181 in a different communication channel, which providesimproved timing efficiency (“duplex gain”). For instance, using thesecond communication channel frees up the first communication channelfor subsequent transmissions thereon without requiring a wait period(e.g., short interframe space) between an end of the MPDU 180 and abeginning of the acknowledgment 181.

FIG. 2A is a diagram of an example PPDU 200 that the network interfacedevice 122 (FIG. 1) is configured to generate and transmit to one ormore client stations 154 (e.g., the client station 154-1), according toan embodiment. The network interface device 162 (FIG. 1) may also beconfigured to transmit data units the same as or similar to the PPDU 200to the AP 114. The PPDU occupies a 20 MHz bandwidth or another suitablebandwidth, in an embodiment. Data units similar to the PPDU 200 occupyother suitable bandwidth such as 40 MHz, 60 MHz, 80 MHz, 100 MHz, 120MHz, 140 MHz, 160 MHz, 180 MHz, 200 MHz, etc., for example, in otherembodiments.

The PPDU 200 includes a PHY preamble 204 and a PHY data portion 208. ThePHY preamble 204 includes at least one of a legacy portion 212 and anon-legacy portion 216, in at least some embodiments. In an embodiment,the legacy portion 212 is configured to be processed by legacycommunication devices in the WLAN 110 (i.e., communication devices thatoperate according to a legacy communication protocol), enabling thelegacy communication devices to detect the PPDU 200 and to obtain PHYinformation corresponding to the PPDU 200, such as a duration of thePPDU 200.

FIG. 2B is a diagram of an example PHY preamble 220. In an embodiment,the PHY preamble 220 corresponds to the PHY preamble 204. In anembodiment, the PHY preamble 220 is included in the legacy portion 212.In another embodiment, the PHY preamble 220 is included in thenon-legacy portion 216. The PHY preamble 220 includes one or more shorttraining fields (STFs) 224, one or more long training field (LTFs) 228,and one or more signal fields (SIGs) 232. In an embodiment, the STFs 224and the LTFs 228 are used for packet detection, automatic gain control(AGC), frequency offset estimation, channel estimation, etc. In anembodiment, the number of LTFs in the LTFs 228 correspond to a number ofspatial/space-time streams used for transmission of the PPDU 200. In anembodiment, the SIGs 232 are used to signal PHY communication parameters(e.g., a modulation and coding scheme (MCS), a number of spatialstreams, a frequency bandwidth, etc.) corresponding to the PPDU 200.

In some embodiments, the PHY preamble 220 omits one or more of thefields 224-232. In some embodiments, the PHY preamble 220 includes oneor more additional fields not illustrated in FIG. 2B. In someembodiments, the order of the fields 224-232 is different thanillustrated in FIG. 2B. In an embodiment, the PPDU 200 is generated andtransmitted as a sequence of orthogonal frequency division multiplexing(OFDM) symbols. In an embodiment, each of the STF 224, the LTF 228, theSIG 232, and the data portion 208 comprises one or more OFDM symbols.

In an embodiment, the PPDU 200 is a multi-user (MU) orthogonal frequencydivision multiple access (OFDMA) data unit in which independent datastreams are transmitted to multiple client stations 154 using respectivesets of OFDM tones allocated to the client stations 154. For example, inan embodiment, available OFDM tones (e.g., OFDM tones that are not usedas DC tone and/or guard tones) are segmented into multiple resourceunits (RUs), and each of the multiple RUs is allocated to data to one ormore client stations 154. In an embodiment, the independent data streamsin respective allocated RUs are further transmitted using respectivespatial streams, allocated to the client stations 154, usingmultiple-input multiple-output (MIMO) techniques. In an embodiment, thePPDU 200 is a MU-MIMO PHY data unit in which independent data streamsare transmitted to multiple client stations 154 using respective spatialstreams allocated to the client stations 154.

In an embodiment, an operating frequency band of a communication devicein the WLAN 110 is divided into a plurality of smaller componentchannels. In an embodiment, the operating frequency band is divided intocomponent channels, each corresponding to a width of 20 MHz, or anothersuitable frequency bandwidth. Multiple component channels may beconcatenated to form a wider channel. For instance, a 40 MHz channel maybe formed by combining two 20 MHz component channels, an 80 MHz channelmay be formed by combining two 40 MHz channels, a 160 MHz channel may beformed by combining two 80 MHz channels. In an embodiment, the operatingfrequency band is divided into component channels of a width differentthan 20 MHz.

In an embodiment, the PPDU 200 has a 20 MHz frequency bandwidth and istransmitted in a 20 MHz channel. In other embodiments, the PPDU 200 mayhave a frequency bandwidth of 40 MHz, 80 MHz, 100 MHz, 120 MHz, etc.,and is correspondingly transmitted over a 40 MHz, 80 MHz, 100 MHz, 120MHz, etc., channel, respectively. In some such embodiments, at least aportion of the PPDU 200 (e.g., at least a legacy portion of the PHYpreamble 204, or the entirety of the PHY preamble 204) is generated bygenerating a field corresponding to a 20 MHz component channel bandwidthand repeating the field over a number of 20 MHz component channelscorresponding to the transmission channel, in an embodiment. Forexample, in an embodiment in which the PPDU 200 occupies an 80 MHzchannel, at least the legacy portion 212 corresponding to the 20 MHzcomponent channel bandwidth is replicated in each of four 20 MHzcomponent channels that comprise the 80 MHz channel.

In an embodiment, one or more communication devices in the WLAN 110(e.g., the AP 114, the client station 154, etc.) are configured forvarious multi-channel operations. In an embodiment, multi-channeloperation includes multi-band communication, i.e., operating accordingto a communication protocol that permits concurrent operation of asingle wireless network across multiple RF bands and includes hardwarethat is configured to provide concurrent communications over multiple RFbands. Such communication devices are referred to herein as “multi-bandcommunication devices” or frequency division duplexing (FDD)communication devices. In an embodiment, at least one client station 154(e.g., the client station 154-3) may include hardware or may operateaccording to a communication protocol (e.g., a legacy communicationprotocol) that is not configured for multi-band communications (i.e.,the protocol only permits a wireless network to operate in a single RFband at a given time), and may operate only in one of the multiple RFbands (at a given time) being used by multi-band devices. Suchcommunication devices are referred to herein as “single-bandcommunication devices”.

In an embodiment, one or more communication devices in the WLAN 110(e.g., the AP 114, the client station 154, etc.) are configured forvarious multi-channel operations. In an embodiment, multi-channeloperation corresponds asynchronous dual-band concurrent (DBC) operationover two or more communication channels. For instance, in an embodiment,the AP 114 is configured to transmit a first signal in a firstcommunication channel, and simultaneously transmit a second signal overa second communication channel. In an embodiment, the AP 114 isconfigured to transmit a first signal in a first communication channel,and simultaneously receive a second signal over a second communicationchannel. In an embodiment, the AP 114 is configured to receive a firstsignal in a first communication channel, and simultaneously receive asecond signal over a second communication channel. In any of the abovecases corresponding to DBC operation, the transmission/reception of thefirst signal and the second signal may be asynchronous. For instance, inan embodiment, one or both of corresponding start times and end times ofthe first signal and the second signal may be different.

In various embodiments, multiple different frequency bands within the RFspectrum are employed for signal transmissions within the WLAN 110. Inan embodiment, different communication devices (i.e., the AP 114 and theclient stations 154) may be configured for operation in differentfrequency bands (e.g., radio frequency bandwidths). In an embodiment, atleast some communication devices (e.g., the AP 114 and the clientstation 154) in the WLAN 110 may be configured for operation overmultiple different frequency bands. In an embodiment, the firstcommunication channel is separated in frequency from the secondcommunication channel, i.e., there is a gap in frequency between thefirst communication channel and the second communication channel (inother words, the first communication channel is not contiguous with thesecond communication channel). In an embodiment, the first communicationchannel and the second communication channel do not overlap each other.

Exemplary frequency bands include, a first frequency band correspondingto a frequency range of approximately 2.4 GHz-2.5 GHz (“2 GHz band”),and a second frequency band corresponding to a frequency range ofapproximately 5 GHz-5.9 GHz (“5 GHz band”) of the RF spectrum. In anembodiment, one or more communication devices within the WLAN may alsobe configured for operation in a third frequency band in the 6 GHz-7 GHzrange (“6 GHz band”). Each of the frequency bands comprise multiplecomponent channels which may be combined within the respective frequencybands to generate channels of wider bandwidths, as described above. Inan embodiment corresponding to multi-channel operation over a firstcommunication channel and a second communication channel, the firstcommunication channel and the second communication channel may be inseparate frequency bands, or within a same frequency band.

In an embodiment, the first communication channel and the secondcommunication channel have different frequency bandwidths (e.g., 80 MHzand 20 MHz, 80 MHz and 40 MHz, 160 MHz and 20 MHz, or other suitablebandwidths). In an embodiment, the first communication channel and thesecond communication channel consist of respective different numbers ofcomponent channels.

FIG. 3 is a diagram of a system architecture corresponding to acommunication device 300 configured for DBC operation (e.g., amulti-band communication device). In an embodiment, the communicationdevice 300 corresponds to the AP 114. In another embodiment, thecommunication device 300 corresponds to the client station 154-1. In anembodiment, the communication device 300 is configured for operationover two or more RF bands. For example, in an embodiment, thecommunication device 300 is configured to communicate via a first WLANcommunication channel having a first RF bandwidth and via a second WLANcommunication channel having a second RF bandwidth that does not overlapthe first RF bandwidth. In some embodiments, the communication device300 includes a packet forwarding processor 304 configured to forwardpackets among the two RF bands and another network connection (e.g., awired connection or wide area network connection, not shown). Thecommunication device 300 also includes a first MAC processor 308(MAC-1), a second MAC processor 312 (MAC-2), a first PHY processor 316,and a second PHY processor 320. The first MAC processor 308 is coupledto the first PHY processor 316, and the second MAC processor 312 iscoupled to the second PHY processor 320. The first MAC processor 308exchanges frames with the first PHY processor 316, and the second MACprocessor 312 exchanges frames with the second PHY processor 320.

In an embodiment, first MAC processor 308 and the second MAC processor312 correspond to the MAC processor 126 of FIG. 1. In anotherembodiment, the first MAC processor 308 and the second MAC processor 312correspond to the MAC processor 166 of FIG. 1. In an embodiment, thefirst PHY processor 316 and the second PHY processor 320 correspond tothe PHY processor 130 of FIG. 1. In another embodiment, the first PHYprocessor 316 and the second PHY processor 320 correspond to the PHYprocessor 170 of FIG. 1.

The first PHY processor 316 includes a first baseband signal processor324 (Baseband-1) coupled to a first RF radio 328 (Radio-1). The secondPHY processor 320 includes a second baseband signal processor 332(Baseband-2) coupled to a second RF radio 336 (Radio-2). In anembodiment, the RF radio 328 and the RF radio 336 correspond to thetransceivers 134 of FIG. 1. In another embodiment, the RF radio 328 andthe RF radio 336 correspond to the transceivers 174 of FIG. 1. In someembodiments, the RF radio 328 is configured to operate on a first RFband, and the RF radio 336 is configured to operate on a second RF band.In an embodiment, the first RF band is different from the second RFband, for example, the first RF band does not overlap the second RFband. In a further embodiment, the first RF band is separated from thesecond RF band by a frequency gap of, for example, 10 MHz, 20 MHz, 500MHz, or another suitable frequency gap. In an embodiment, the frequencygap includes one or more communication channels that are not used by thecommunication device 300, but are used by other communication devices,for example, other WLAN access points, WLAN client stations, or otherwireless communication devices (not shown). In another embodiment, theRF radio 328 and the RF radio 336 are both configured to operate on thesame RF band.

The MAC-1 308 is configured to generate frames and to provide the framesto the Baseband-1 324. The Baseband-1 324 is configured to receiveframes from the MAC-1 308, generate a baseband signal corresponding toPPDUs. The Radio-1 328 upconverts the baseband signal and generates RFsignals corresponding to the PPDUs for transmission over the firstcommunication channel via one or more antennas (not shown). Similarly,the Radio-1 328 is configured to receive RF signals corresponding toPPDUs received over the first communication channel via the one or moreantennas and generate a baseband signal corresponding to the receivedPPDUs. The Baseband-1 324 decodes and de-encapsulates the PPDUs togenerate frames and provides the frames to the MAC-1 308. The MAC-1 308processes the frames.

Operations of the MAC-2 312, the Baseband-2 332, and the Radio-2 336correspond to operations of the MAC-1 308, the Baseband-1 324, and theRadio-1 328 as described above, except that the MAC-2 312, theBaseband-2 332, and the Radio-2 336 operate in the second communicationchannel. For instance, MAC-2 312, the Baseband-2 332, and the Radio-2336 generate/transmit PPDUs and receive/process PPDUstransmitted/received over the second communication channel.

In an embodiment corresponding to DBC operation, the MAC-1 308, theBaseband-1 324, the MAC-2 312, and the Baseband-2 332 are configured forasynchronous operation in the first communication channel and the secondcommunication channel. For instance, transmissions/receptions in thefirst communication channel are not synchronized or coordinated withtransmissions/receptions in the second communication channel, accordingto an embodiment. For instance, the MAC-1 308 and the MAC-2 312 do notcoordinate media access control functions, and the Baseband-1 324 andthe Baseband-2 332 do not coordinate transmission timing, according toan embodiment.

In an embodiment, the forwarding processor 304 is omitted and the MAC-1308 and the MAC-2 312 are coupled to another suitable processor (e.g.,the host processor 118 (FIG. 1)) that performs one or more higher leveloperations corresponding to data transmission and reception over themultiple communication channels. For instance, in an embodiment, theprocessor performs one or more operations corresponding to Layer 3 andabove, as characterized in the Open Systems Interconnection (OSI) model.

Although only two MAC processors and two PHY processors are shown inFIG. 3, the communication device 300 has three, four, or more MACprocessors and PHY processors that are configured to communicate onthree, four, or more respective communication channels, in variousembodiments. In an embodiment, for example, the communication device 300includes i) the MAC processor 308 and PHY processor 316 configured tooperate in the 2.4 GHz band, ii) the MAC processor 312 and PHY processor320 configured to operate in the 5 GHz band, and iii) a MAC processor(not shown) and PHY processor (not shown) configured to operate in the 6GHz band (or another suitable band).

FIG. 4A is a diagram of an example system architecture corresponding toa communication device 400 configured for multi-channel operation (e.g.,a multi-band communication device), according to an embodiment. Forinstance, in an embodiment, the communication device 400 is configuredfor synchronous or asynchronous transmission/reception over aggregatedcommunication channels. In an embodiment, the communication device 400corresponds to the AP 114. In another embodiment, the communicationdevice 400 corresponds to the client station 154-1.

In an embodiment, the communication device 400 is configured foroperation over two or more communication channels and includes aforwarding processor 404. The communication device 400 also includes asingle MAC processor 408, a first PHY processor 416, and a second PHYprocessor 420. The single MAC processor 408 is coupled to the first PHYprocessor 416 and the second PHY processor 420. The single MAC processor408 exchanges frames with the first PHY processor 416 and the second PHYprocessor 420.

In an embodiment, the single MAC processor 408 corresponds to the MACprocessor 126 of FIG. 1. In another embodiment, the single MAC processor408 corresponds to the MAC processor 166 of FIG. 1. In an embodiment,the first PHY processor 416 and the second PHY processor 420 correspondto the PHY processor 130 of FIG. 1. In another embodiment, the first PHYprocessor 416 and the second PHY processor 420 correspond to the PHYprocessor 170 of FIG. 1.

The first PHY processor 416 includes a first baseband signal processor424 (Baseband-1) coupled to a first RF radio 428 (Radio-1). The secondPHY processor 420 includes a second baseband signal processor 432(Baseband-2) coupled to a second RF radio 436 (Radio-2). In anembodiment, the RF radio 428 and the RF radio 436 correspond to thetransceivers 134 of FIG. 1. In an embodiment, the RF radio 428 isconfigured to operate on a first RF band, and the RF radio 436 isconfigured to operate on a second RF band. In another embodiment, the RFradio 428 and the RF radio 436 are both configured to operate on thesame RF band.

Although only two PHY processors 416 and 420 are shown in the embodimentof FIG. 4A, in another embodiment, the communication device 400 includesone or more additional PHY processors (not shown), for instance, a thirdPHY processor (not shown) configured to operate on yet another RF bandthat is different from the first and second RF bands. In an embodiment,for example, the first, second, and third PHY processors are configuredto operate on the 2.4 GHz, 5 GHz, and 6 GHz bands, respectively. Inother embodiments, other suitable bands are utilized (e.g., 60 GHz,“sub-1 GHz” or 900 MHz, 3.6 GHz, 4.9 GHz, etc.).

In an embodiment, the MAC processor 408 generates and parses datacorresponding to MAC layer data units (e.g., frames) into a plurality ofdata streams corresponding to respective communication channels. The MACprocessor 408 provides the parsed data streams to the Baseband-1 424 andthe Baseband-2 432. The Baseband-1 424 and the Baseband-2 432 areconfigured to receive the respective data streams from the MAC processor408, and encapsulate and encode the respective data streams to generaterespective baseband signals corresponding to PPDUs. In an embodiment,the respective baseband signals have different bandwidths. TheBaseband-1 424 and the Baseband-2 432 provide the respective basebandsignals to the Radio-1 428 and the Radio-2 436. The Radio-1 428 andRadio-2 436 upconvert the respective baseband signals to generaterespective RF signals for transmission via the first communicationchannel and the second communication channel, respectively. The Radio-1428 transmits a first RF signal via the first communication channel andthe Radio-2 436 transmits a second RF signal via a second communicationchannel.

The communication device 400 also includes synchronization controlcircuitry 440, in some embodiments. The synchronization controlcircuitry 440 is configured to ensure that respective transmittedsignals over the first communication channel and the secondcommunication channel are synchronized. The synchronization controlcircuitry 440 is coupled to the Baseband-1 424 and the Baseband-2 432 toensure that the respective baseband signals are synchronized in time. Insome embodiments, the synchronization control circuitry 440 ensures thatsome transmitted signals are synchronized, while other transmittedsignals are not synchronized.

The Radio-1 428 and the Radio-2 436 are also configured to receiverespective RF signals via the first communication channel and the secondcommunication channel, respectively. The Radio-1 428 and the Radio-2 436generate respective baseband signals corresponding to the respectivereceived signals. In an embodiment, the generated respective basebandsignals have different bandwidths. The generated respective basebandsignals are provided to the respective baseband signal processorsBaseband-1 424 and Baseband-2 432. The Baseband-1 424 and the Baseband-2432 generate respective data streams that are provided to the MACprocessor 408. The MAC processor 408 processes the respective datastreams. In an embodiment, the MAC processor 408 deparses the datastreams received from the Baseband-1 424 and the Baseband-2 432 into asingle information bit stream.

In an embodiment, the forwarding processor 404 is omitted and the MACprocessor 408 is coupled to another suitable processor (e.g., the hostprocessor 118 (FIG. 1)) that performs one or more higher leveloperations corresponding to data transmission and reception. Forinstance, in an embodiment, the other processor performs one or moreoperations corresponding to Layer 3 and above as characterized in theOSI model.

FIG. 4B is a diagram of an example system architecture corresponding toa communication device 450 configured for multi-channel operation (e.g.,a multi-band communication device), according to another embodiment. Forinstance, in an embodiment, the communication device 450 is configuredfor synchronous or asynchronous transmission/reception over aggregatedcommunication channels. In an embodiment, the communication device 450corresponds to the AP 114. In another embodiment, the communicationdevice 450 corresponds to the client station 154-1. The communicationdevice 450 is similar to the communication device 400 of FIG. 4A, andlike-numbered elements are not discussed in detail for purposes ofbrevity.

The communication device 450 includes a single MAC processor 458 coupledto a PHY processor 466. The single MAC processor 408 exchanges frameswith the PHY processor 466. In an embodiment, the single MAC processor458 corresponds to the MAC processor 126 of FIG. 1. In anotherembodiment, the single MAC processor 458 corresponds to the MACprocessor 166 of FIG. 1. In an embodiment, the PHY processor 466corresponds to the PHY processor 130 of FIG. 1. In another embodiment,the PHY processor 466 corresponds to the PHY processor 170 of FIG. 1.The PHY processor 466 includes a single baseband signal processor 474.The single baseband signal processor 474 is coupled to the Radio-1 428and the Radio-2 436.

In an embodiment, the MAC processor 458 generates data corresponding toMAC layer data units (e.g., frames) and provides the frames to thebaseband signal processor 474. The baseband signal processor 474 isconfigured to receive frames from the MAC processor 458, and parse datacorresponding to the frames into a plurality of bit streams. Thebaseband signal processor 474 is also configured to encapsulate andencode the respective bit streams to generate respective basebandsignals corresponding to PPDUs. In an embodiment, the respectivebaseband signals have different bandwidths. The baseband signalprocessor 474 provides the respective baseband signals to the Radio-1428 and the Radio-2 436. The Radio-1 428 and Radio-2 436 upconvert therespective baseband signals to generate respective RF signals fortransmission via the first communication channel and the secondcommunication channel, respectively. The Radio-1 428 transmits a firstRF signal via the first communication channel and the Radio-2 436transmits a second RF signal via a second communication channel.

The baseband signal processor 474 is configured to ensure thatrespective transmitted signals over the first communication channel andthe second communication channel are synchronized, in some embodiments.For example, the baseband signal processor 474 is configured to generatethe respective baseband signals such that the respective basebandsignals are synchronized in time.

The Radio-1 428 and the Radio-2 436 are also configured to receiverespective RF signals via the first communication channel and the secondcommunication channel, respectively. The Radio-1 428 and the Radio-2 436generate respective baseband signals corresponding to the respectivereceived signals. In an embodiment, the generated respective basebandsignals have different bandwidths. The generated respective basebandsignals are provided to the baseband signal processor 474. The basebandsignal processor 474 generate respective bit streams, and de-parse thebit streams into a data stream corresponding to frames. The basebandsignal processor 474 provides the frames to the MAC processor 458. TheMAC processor 458 processes the frames.

Although only two RF radios 428 and 436 are shown in the embodiment ofFIG. 4B, in another embodiment, the communication device 400 includesone or more additional RF radios (not shown), for instance, a third RFradio (not shown) configured to operate on yet another RF band that isdifferent from the first and second RF bands. In an embodiment, forexample, the first, second, and third RF radios are configured tooperate on the 2.4 GHz, 5 GHz, and 6 GHz bands, respectively. In otherembodiments, other suitable bands are utilized (e.g., 60 GHz, “sub-1GHz” or 900 MHz, 3.6 GHz, 4.9 GHz, etc.).

FIG. 5 is a diagram of an example synchronized transmission sequence 500over aggregated communication channels, according to an embodiment. Inan embodiment, the transmission sequence 500 is generated andtransmitted by the network interface device 122 (FIG. 1) to one or moreclient stations 154 (e.g., the client station 154-1). In an embodiment,the network interface device 122 generating the transmission sequence500 has a structure of the communication device 400 (FIG. 4A). Inanother embodiment, the network interface device 122 generating thetransmission sequence 500 has a structure of the communication device450 (FIG. 4B). In another embodiment, the transmission sequence 500 isgenerated and transmitted by the network interface device 162 (FIG. 1)to the AP 114. In an embodiment, the network interface device 162generating the transmission sequence 500 has a structure of thecommunication device 400 (FIG. 4A). In another embodiment, the networkinterface device 162 generating the transmission sequence 500 has astructure of the communication device 450 (FIG. 4B).

In an embodiment, the transmission sequence 500 corresponds to a singleuser (SU) transmission that is generated and transmitted to a singlecommunication device. In an embodiment, the transmission sequence 500corresponds to a multi-user (MU) transmission that includes data formultiple communication devices (e.g., the client stations 154). Forexample, in an embodiment, the MU transmission sequence 500 is an OFDMAtransmission. In another embodiment, the MU transmission sequence 500 isa MU-MIMO transmission.

In the embodiment shown in FIG. 5, the transmission sequence 500includes a downlink transmission 502 and an uplink transmission 503. Inanother embodiment, the directions of the transmissions 502 and 503 arereversed so that the transmission 502 is an uplink transmission and thetransmission 503 is a downlink transmission. The downlink transmission502 includes a first RF signal 504 in a first communication channel 508and a second RF signal 512 in a second communication channel 516. Thefirst RF signal 504 comprises a PHY preamble 420 and a PHY data portion424. The second RF signal 512 comprises of a PHY preamble 528, a dataportion 532, and optional padding 536. The uplink transmission 503includes a third RF signal 506 in the first communication channel 508and a fourth RF signal 514 in the second communication channel 516. Thethird RF signal 506 comprises a PHY preamble 540 and a PHY data portion544. The second RF signal 512 comprises a PHY preamble 548 and a dataportion 552. In an embodiment, the first and second RF signals 504 and512 include correspond to downlink MPDUs transmitted to a client station154, while the third and fourth RF signals 506 and 514 correspond toacknowledgments of the downlink MPDUs (e.g., the respective PHY dataportions include ACK frames, block ACK frames, or other suitableacknowledgments) transmitted by the client station 154. In anembodiment, the client station 154 transmits the third and fourth RFsignals 506 and 514 after a short interframe space (SIFS), for example,to allow a suitable time for the client station 154 to process andgenerate the third and fourth RF signals 506 and 514.

In an embodiment, transmission of the first RF signal 504 and the secondRF signal 512 are synchronized such that they start at a same timeinstance t₁ and end at a same time instance t₃. In an embodiment, thetransmission sequence 500 is further synchronized such that the PHYpreamble 520 and the PHY preamble 528 are of a same duration. In anembodiment in which the PHY data portion 532 has a shorter duration thanthe PHY data portion 524, the PHY data portion 532 is appended with thepadding 536 so that transmission of the signal 512 ends at t₃.

In an embodiment, the PHY preamble 520 and the PHY preamble 528 areformatted in a manner similar to the PHY preamble 204 of FIG. 2. In anembodiment, at least a portion of the PHY preamble 520 and at least aportion of the PHY preamble 528 have the same structure and/or includethe same information. In an embodiment, at least a portion of the PHYpreamble 520 and at least a portion of the PHY preamble 528 areidentical.

In various embodiments, the first communication channel 508 and thesecond communication channel 516 are in different RF bands or areco-located in a same RF band. In an embodiment, the RF band(s)correspond to the 2 GHz band, the 5 GHz band, the 6 GHz band, or othersuitable band, as described above. The first communication channel 508and the second communication channel 516 may each be comprised of one ormore of component channels. In an embodiment, a frequency bandwidth ofthe first communication channel 508 (i.e., a frequency bandwidth of thefirst RF signal 504 and third RF signal 506) is different than afrequency bandwidth of the second communication channel 516 (i.e., afrequency bandwidth of the second RF signal 512 and the fourth RF signal514). In various embodiments, for example, respective RF bandwidths ofthe first communication channel 508 and the second communication channel516 are 80 MHz and 20 MHz, 160 MHz and 20 MHz, 320 MHz and 40 MHz, orother suitable bandwidths. In another embodiment, the RF bandwidth ofthe first communication channel 508 is the same as the RF bandwidth ofthe second communication channel 516.

In an embodiment, the first communication channel 508 and the secondcommunication channel 516 do not overlap. In a further embodiment, thefirst communication channel 508 and the second communication channel 516are separated in frequency, e.g., the channels are non-contiguous. Forexample, a gap Δf in frequency exists between the first communicationchannel 508 and the second communication channel 516. In variousembodiments, the gap Δf is at least 500 kHz, at least 1 MHz, at least 5MHz, at least 20 MHz, etc. In some embodiments, the gap Δf is 320 MHz,500 MHz, 1 GHz, or more, for example, where the first communicationchannel 508 is within the 2.4 GHz band and the second communicationchannel 516 is within the 5 GHz band.

In some embodiments, the first RF signal 504 is transmitted via a firstnumber of spatial or space-time streams (hereinafter referred to as“spatial streams” for brevity), and the second RF signal 512 istransmitted via a second number of spatial streams that is differentthan the first number of spatial streams. In one such embodiment, thePHY preamble 520 and the PHY preamble 528 comprise a same number of LTFseven when the first RF signal 504 is transmitted via a first number ofspatial streams and the second RF signal 512 is transmitted via a secondnumber of spatial streams that is different than the first number ofspatial streams. In an embodiment, the same number of LTFs correspond toone of the first signal 404 and the second signal 412 with the largernumber of spatial streams. In other embodiments, the first RF signal 504and the second RF signal 512 are transmitted via a same number ofspatial streams.

In an embodiment, at least the PHY data portion 524 and at least the PHYdata portion 532 employ different encoding schemes and/or modulationschemes. As an example, in an embodiment, the PHY data portion 524 isgenerated using a first MCS and the PHY data portion 432 is generatedusing a second, different MCS. In other embodiments, the PHY dataportion 524 and the PHY data portion 532 are generated using a same MCS.

In an embodiment, the transmission sequence 500 corresponds to a singlePPDU, where a first frequency portion of the single PPDU is transmittedvia the first channel 508 and a second frequency portion of the singlePPDU is transmitted via the second channel 516. In another embodiment,the first RF signal 504 corresponds to a first PPDU and the second RFsignal 512 corresponds to a second PPDU. In an embodiment, each of thePHY preambles 520 and 528, and the PHY data portions 524 and 532, arecomprised of one or more OFDM symbols.

In various embodiments, the communication device 400 (FIG. 4A) isconfigured to generate at least a portion of the transmission sequence500 and to receive at least a portion of the transmission sequence 500.In an embodiment, for example, the communication device 400synchronously transmits the RF signals 504 and 512 and receives the RFsignals 506 and 514. In another embodiment, the communication device 400receives the RF signals 504 and 512 and synchronously transmits the RFsignals 506 and 514.

In another embodiment, the communication device 450 (FIG. 4B) isconfigured to generate at least a portion of the transmission sequence500 and to receive at least a portion of the transmission sequence 500.In an embodiment, for example, the communication device 450synchronously transmits the RF signals 504 and 512 and receives the RFsignals 506 and 514. In another embodiment, the communication device 450receives the RF signals 504 and 512 and synchronously transmits the RFsignals 506 and 514.

FIG. 6 is a diagram of an example signal transmission sequence 600 overaggregated communication channels using frequency division duplexing,according to an embodiment. In the embodiment shown in FIG. 6, thetransmission sequence 600 includes transmissions 602, 603, and 604,where the transmissions 602 and 604 are downlink transmissions (e.g.,from the AP 114 to one or more client stations 154) in a firstcommunication channel 608 and the transmission 603 is an uplinktransmission (e.g., from the client stations 154 to the AP 114) in asecond communication channel 616. In other words, the firstcommunication channel 608 of the aggregated communication channels isdesignated for downlink traffic and the second communication channel 616of the aggregated communication channels is designated for uplinktraffic. The communication channels 608 and 616 are similar to thecommunication channels 508 and 516 described above with respect to FIG.5. Accordingly, the communication channels 608 and 616 are in differentRF bands (e.g.,2 GHz, 5 GHz, 6 GHz, etc.), in various embodiments.

In another embodiment, the transmissions 602 and 604 are uplinktransmissions and the transmission 603 is a downlink transmission. Inother words, the first communication channel 608 is designated foruplink traffic and the second communication channel 616 is designatedfor downlink traffic. In yet another embodiment, the first communicationchannel 608 is designated for forward traffic and the secondcommunication channel 616 is designated for reverse traffic (e.g.,acknowledgments to the forward traffic). In other words, managementframes and data frames are transmitted on the first communicationchannel 608 regardless of whether they are transmitted by the AP 114 orby the client station 154, while acknowledgment frames are similarlytransmitted on the second communication channel 616. In someembodiments, the AP 114 transmits a trigger frame (e.g., trigger frame742, FIG. 7) to one or more client stations 154 to trigger an uplinktransmission (e.g., uplink transmission 603).

In the embodiment shown in FIG. 6, the downlink transmission 602includes a first RF signal 620 having a PHY preamble 622 and PHY dataportion 624, the downlink transmission 604 includes a second RF signal660 having a PHY preamble 662 and a PHY data portion 664, and the uplinktransmission 603 includes a third RF signal 640 having a PHY preamble642 and PHY data portion 644. The PHY preambles 622 and 662 are similarto the PHY preamble 520, while the PHY data portions 624 and 664 aresimilar to the PHY data portion 524.

The PHY preamble 642 is similar to the PHY preamble 540 and the PHY dataportion 644 is similar to the PHY data portion 544. However, in theembodiment shown in FIG. 6, the client station transmits the third RFsignal 660 (i.e., the acknowledgment of the first RF signal 620) in thesecond communication channel 616, instead of the first communicationchannel 608. In some scenarios, the AP 114 and client stations 154designate the first communication channel 608 for forward traffic ordownlink traffic and designate the second communication channel 616 foruplink traffic or reverse traffic when the first communication channel608 has a larger RF bandwidth (e.g., higher data transmission capacity)than the second communication channel 616. In some such scenarios, theoverall throughput of the WLAN 110 is improved because the highercapacity channel (the first communication channel 608) is notmonopolized by the second RF signal 640 and the SIFS period thatprecedes the second RF signal 640 before the third RF signal 660 can betransmitted. In some scenarios, by utilizing frequency divisionduplexing with the first communication channel 608 and the secondcommunication channel 616 with separate RF radios (i.e., RF radios 428and 436) in non-overlapping RF bandwidths, the AP 114 and clientstations 154 have improved MAC protocol efficiency because traffic inboth directions (uplink and downlink, forward and reverse, etc.), suchas the RF signals 640 and 660, can be transmitted and receivedsimultaneously.

In various embodiments, the communication device 400 (FIG. 4A) isconfigured to generate at least a portion of the transmission sequence600 and to receive at least a portion of the transmission sequence 600.In an embodiment, for example, the communication device 400 transmitsthe RF signals 620 and 660 and receives RF signal 640. In anotherembodiment, the communication device 400 receives the RF signals 620 and660 and transmits the RF signal 640.

In some embodiments, the communication device 450 (FIG. 4B) isconfigured to generate at least a portion of the transmission sequence600 and to receive at least a portion of the transmission sequence 600.In an embodiment, for example, the communication device 450 transmitsthe RF signals 620 and 660 and receives RF signal 640. In anotherembodiment, the communication device 450 receives the RF signals 620 and660 and transmits the RF signal 640.

In an embodiment, the communication device 400 or the communicationdevice 450 is configured to select the bands of the first and secondcommunication channels 608 and 616 so that interference between thecommunication channels is reduced. In an embodiment, for example, whenthe 2.4 GHz band, the 5 GHz band, and 6 GHz band are available, thecommunication device 400 selects the 6 MHz band and the 2.4 GHz band forthe first and second communication channels 608 and 616, respectively,so that interference between the communication channels is reduced.

In an embodiment, the communication device 400 or 450 is configured toselect RF bandwidths for the first and second communication channels 608and 616 so that interference between the communication channels isreduced (e.g., interference caused by the simultaneous reception of thethird RF signal 603. In an embodiment, for example, the communicationdevice 400 selects a 320 MHz bandwidth in an upper frequency range ofthe 6 GHz band (e.g., 6530-6850 MHz) for the first communication channel608 and selects a 40 MHz bandwidth in a lower frequency range of the 5GHz band (e.g., 5150 MHz to 5190 MHz) for the second communicationchannel 616. In another embodiment, for example, the communicationdevice 400 selects an 80 MHz bandwidth in an upper frequency range ofthe 5 GHz band (e.g., 5735-5815 MHz) for the first communication channel608 and selects a 20 MHz bandwidth in a lower frequency range of the 5GHz band (e.g., 5190 MHz to 5210 MHz) for the second communicationchannel 616.

FIG. 7 is a diagram of an example MU transmission sequence 700 over anaggregated communication channel using frequency division duplexing,according to an embodiment. In the embodiment shown in FIG. 7, thetransmission sequence 700 includes transmissions 702, 703, and 704,where the transmissions 702 and 704 are downlink transmissions (e.g.,from the AP 114 to one or more client stations 154 referred to as STA1,STA2, and STA3) and the transmission 703 is an uplink transmission(e.g., from the client stations 154 to the AP 114). In this embodiment,the first communication channel 708 of the aggregated communicationchannels is designated for downlink traffic and the second communicationchannel 716 of the aggregated communication channels is designated foruplink traffic and optionally, triggers for the uplink traffic. Thecommunication channels 708 and 716 are similar to the communicationchannels 508 and 516 described above with respect to FIG. 5.Accordingly, the communication channels 708 and 716 are in different RFbands (e.g., 2 GHz, 5 GHz, 6 GHz, etc.), in various embodiments.

In an embodiment, the transmission sequence 700 is generated andtransmitted by the network interface device 122 (FIG. 1) to a pluralityof client stations 154. In another embodiment, the transmission sequence700 is generated and transmitted by the network interface device 162(FIG. 1) to a plurality of other client stations 154 and optionally theAP 114.

In the embodiment shown in FIG. 7, the downlink transmission 702includes a first RF signal 720 having a PHY preamble 722 and PHY dataportion 724 in a first communication channel 708, the downlinktransmission 704 includes a second RF signal 740 having a PHY preamble742 and PHY data portion 744 in a second communication channel 716, andthe uplink transmission 703 includes a third RF signal 760 having a PHYpreamble 762 and PHY data portion 764 in the second communicationchannel 716. In an embodiment, the PHY data portion 724 corresponds to adownlink MPDU and the PHY data portion 764 corresponds to anacknowledgment of the downlink MPDU, while the PHY data portion 744corresponds to a trigger frame that triggers the acknowledgment.

In various embodiments, the first communication channel 708 and thesecond communication channel 716 are similar to the first communicationchannels 508 and 608 and the second communication channels 516 and 616,respectively, as described above with reference to FIG. 5 and FIG. 6. Inan embodiment, for example, the first communication channel 708 isdesignated for downlink traffic and the second communication channel 716is designated for uplink traffic. In another embodiment, the firstcommunication channel 708 is designated for forward traffic and thesecond communication channel 716 is designated for reverse traffic.

The PHY preambles 722, 742, and 762 are similar to the PHY preamble 520.In an embodiment in which the first communication channel 708 comprisesmultiple component channels, at least a portion of the PHY preamble 722(e.g., a legacy portion) is generated by generating a fieldcorresponding to one component channel and duplicating the field overone or more other component channels corresponding to the firstcommunication channel 708. In an embodiment in which the secondcommunication channel 716 comprises multiple component channels, atleast a portion of the PHY preamble 742 or 762 (e.g., a legacy portion)is generated by generating a field corresponding to one componentchannel and duplicating the field over one or more other componentchannels corresponding to the second communication channel 716.

In various embodiments, the first communication channel 708 and thesecond communication channel 716 are in different RF bands or areco-located in a same RF band. In an embodiment, the RF band(s)correspond to the 2 GHz band, the 5 GHz band, and the 6 GHz bands, asdescribed above. The first communication channel 708 and the secondcommunication channel 716 may each be comprised of one or more ofcomponent channels. In an embodiment, a frequency bandwidth of the firstcommunication channel 708 (i.e., a frequency bandwidth of the first RFsignal 720) is different than a frequency bandwidth of the secondcommunication channel 716 (i.e., a frequency bandwidth of the second RFsignal 740 and third RF signal 760). In another embodiment, thefrequency bandwidth of the first communication channel 708 is the sameas the frequency bandwidth of the second communication channel 716.

In an embodiment, the first communication channel 708 and the secondcommunication channel 716 are separated in frequency. For example, a gapΔf in frequency exists between the first communication channel 708 andthe second communication channel 716. In various embodiments, the gap Δfis at least 500 kHz, at least 1 MHz, at least 5 MHz, at least 20 MHz,etc.

In some embodiments, the transmission sequence 700 utilizes MU-MIMO, forexample, the first RF signal 720 is transmitted via a first number ofspatial streams, and the second RF signal 740 and third RF signal 760are transmitted via a second number of spatial streams that is differentthan the first number of spatial streams. In one such embodiment, thePHY preamble 722 and the PHY preambles 742 and 762 comprise a samenumber of LTFs even when the first RF signal 720 is transmitted via afirst number of spatial streams and the second and third RF signals 740and 760 are transmitted via a second number of spatial streams that isdifferent than the first number of spatial streams. In an embodiment,the same number of LTFs correspond to one of the first RF signal 720 andthe second and third RF signals 740 and 760 with the larger number ofspatial streams. In other embodiments, the first RF signal 720 and thesecond and third RF signals 740 and 760 are transmitted via a samenumber of spatial streams. In an embodiment, at least a PHY payloadportion 724 and at least a PHY data payload 764 employ differentencoding schemes and/or modulation schemes.

In some embodiments, the transmission sequence 700 utilizes OFDMA, forexample, the PHY payload portion 724 includes respective frequencymultiplexed data for respective client stations 154. Individual datawithin the data portion 724 are transmitted to corresponding clientstations 154 in corresponding allocated RUs 724-1, 724-2, and 724-3.Individual data within the data portion 764 are transmitted from thecorresponding client stations 154 in corresponding allocated RUs 764-1,764-2, and 764-3. In various embodiments, some or all of RUs 724/764 usedifferent encoding schemes and/or modulation schemes. As an example, theRU 764-1 and the RU 724-2 are generated using different MCSs and/ordifferent numbers of spatial/space-time streams, etc.

In various embodiments, the communication device 400 (FIG. 4A) isconfigured to generate at least a portion of the transmission sequence700 and to receive at least a portion of the transmission sequence 700.In an embodiment, for example, the communication device 400 transmitsthe RF signals 720 and 740 and receives RF signal 760. In anotherembodiment, the communication device 400 receives the RF signals 720 and740 and transmits the RF signal 760.

In some embodiments, the communication device 450 (FIG. 4A) isconfigured to generate at least a portion of the transmission sequence700 and to receive at least a portion of the transmission sequence 700.In an embodiment, for example, the communication device 450 transmitsthe RF signals 720 and 740 and receives RF signal 760. In anotherembodiment, the communication device 450 receives the RF signals 720 and740 and transmits the RF signal 760.

The multiple communication channels that corresponding to the multipleradios are sometimes referred to herein as “the radio channels” for easeof explanation. In some embodiments, one of the component channelsacross the multiple radio channels is designated as a primary channel.The one radio channel that includes the designated primary channel issometimes referred to herein as “the primary radio channel”. Othercomponent channels across the multiple radio channels that are not aprimary channel are sometimes referred to herein as “secondarychannels”.

FIG. 8A is a diagram of an example channelization scheme 800corresponding to multi-channel operation, according to an embodiment. Inan embodiment, the channelization scheme 800 is employed for signaltransmissions such as described above in reference to FIGS. 5-7, and/orfor other transmissions across multiple radio channels.

The channelization scheme 800 illustrates a first communication channel804 (also referred to herein as “the first radio channel 804”)aggregated with a second communication channel 808 (also referred toherein as “the second radio channel 808”). In various embodiments, theradio channels 804 and 808 correspond to communication channels 508 and516, communication channels 608 and 616, or communication channels 708and 716, as described above in reference to FIG. 5, FIG. 6, and FIG. 7,respectively. In other embodiments, the radio channels 804 and 808correspond to other suitable radio channels.

The first radio channel 804 comprises one or more component channels,and the second radio channel 808 comprises one or more componentchannels. In the channelization scheme 800, a single component channel812 in the radio channel 804 is designated as the primary channel (e.g.,for management frames and control frames). The remaining one or morecomponent channels 816 (if any) in the first radio channel 804 aredesignated as secondary channels 816. Similarly, the one or morecomponent channels 820 in the second radio channel 808 are designated assecondary channels. In an embodiment, the first radio channel 804 andthe second radio channel 808 are separated in frequency as describedabove.

In an embodiment in which the first radio channel 804 and the secondradio channel 808 correspond to different RF bands, and in which one ormore client stations 154 are only capable of operating in only one ofthe RF bands, the AP 114 designates the primary channel to be in the oneradio channel 804/808 that corresponds to the one RF band in which theone or more client stations 154 are only capable of operating. In anembodiment where the first radio channel 804 is in the 5 GHz band andthe second radio channel 808 is in the 6 GHz band, the AP 114 designatesthe primary channel to be in the 5 GHz band when a legacy WLANcommunication device (i.e., a single band station such as an 802.11acclient station or other device that does not support the 6 GHz band). Inan embodiment in which the radio channel 804 and the radio channel 808correspond to different RF bands, and in which one or more clientstations 154 are only capable of operating in only one of the RF bands,the AP 114 is not permitted to designate the primary channel to be in aradio channel 804/808 that does not correspond to the one RF band inwhich the one or more client stations 154 are only capable of operating.

In some embodiments, the WLAN 110 includes i) an AP 114 that is amulti-band communication device and communicates over the first radiochannel 804 and second radio channel 808, ii) a first client station 154that is multi-band communication device and communicates over the firstradio channel 804 and the second radio channel 808, and iii) a secondclient station 154 that is a single-band communication device (i.e., alegacy WLAN communication device) and communicates only over the firstradio channel 804. In an embodiment, the AP 114 designates i) the firstradio channel 804 as a downlink channel and the second radio channel 808as an uplink channel for the first multi-band communication device, andii) the first radio channel 804 as a downlink and uplink channel for thesingle-band communication device. In another embodiment, the AP 114designates i) the first radio channel 804 as a forward channel and thesecond radio channel 808 as a reverse channel for the first multi-bandcommunication device, and ii) the first radio channel 804 as a forwardand reverse channel for the single-band communication device.

FIG. 8B is a diagram of another example channelization scheme 850corresponding to multi-channel operation, according to anotherembodiment. In an embodiment, the channelization scheme 850 is employedfor signal transmissions as described above in reference to FIGS. 5-7.The channelization scheme 850 includes a first communication channel 854(also referred to herein as “the first radio channel 854”) aggregatedwith a second communication channel 858 (also referred to herein as “thesecond radio channel 858”). In various embodiments, the radio channels854 and 858 correspond to communication channels 508 and 516,communication channels 608 and 616, or communication channels 708 and716, as described above in reference to FIG. 5, FIG. 6, and FIG. 7,respectively. In other embodiments, the radio channels 854 and 858correspond to other suitable radio channels.

The first radio channel 854 comprises one or more component channels,and the second radio channel 858 comprises one or more componentchannels. For the channelization scheme 850, the AP 114 designatesrespective primary channels for both radio channels 854 and 858. Forexample, a channel 862 in the first radio channel 854 is designated as aprimary channel corresponding to the first radio channel 854 (sometimesreferred to herein as “the first primary channel 862”), and a componentchannel 866 in the second radio channel 858 is designated as a primarychannel corresponding to second radio channel 858 (sometimes referred toherein as “the second primary channel 866”). The remaining one or morecomponent channels 870 (if any) in the first radio channel 854 aredesignated as secondary channels. Similarly, the one or more componentchannels 874 in the second radio channel 858 are designated as secondarychannels. In an embodiment, the first radio channel 854 and the secondradio channel 858 are separated in frequency as described above.

In an embodiment, the AP 114 operating according to the channelizationscheme 850 transmits beacon frames in both of the primary channels 862and 866. In an embodiment, the beacon frames transmitted in both of theprimary channels 862 and 866 are the same beacon frame.

In some embodiments, at least some communication devices (e.g., clientstations 154) may operate according to a legacy communication protocolthat does not define more than one primary channel for transmission overaggregated channels. In at least some such embodiments, the legacycommunication devices may be allocated for operation in only a singlecommunication channel (e.g., one of the communication channels 854 and858). Alternatively, the legacy communication devices may be configuredfor independent and asynchronous operation in both communicationchannels 854 and 858, such as DBC operation described above.

In some embodiments, the WLAN 110 includes i) an AP 114 that is amulti-band communication device and communicates over the first radiochannel 854 and second radio channel 858, ii) a first client station 154that is multi-band communication device and communicates over the firstradio channel 854 and the second radio channel 858, iii) a second clientstation 154 that is a single-band communication device (i.e., a legacyWLAN communication device) and communicates only over the first radiochannel 854, and iv) a third client station 154 that is a single-bandcommunication device and communicates only over the second radio channel858. In an embodiment, the AP 114 designates i) the first radio channel854 as a downlink channel and the second radio channel 858 as an uplinkchannel for the first, multi-band client station, and ii) the firstradio channel 854 as a downlink and uplink channel for the second,single-band communication device, and iii) the second radio channel 858as a downlink and uplink channel for the third, single-bandcommunication device. In another embodiment, the AP 114 designates i)the first radio channel 854 as a forward channel and the second radiochannel 858 as a reverse channel for the first multi-band communicationdevice, ii) the first radio channel 854 as a forward and reverse channelfor the second, single-band communication device, and iii) the secondradio channel 858 as a forward and reverse channel for the third,single-band communication device.

FIG. 9 is a diagram of an example system architecture corresponding to acommunication device 900 configured for different modes multi-channeloperating modes. In other words, the communication device 900 provides anetwork interface device configured to implement i) a DBC mode asdescribed above with respect to FIG. 3, ii) a synchronous multi-channelmode as described above with respect to FIG. 4A, and/or iii) anasynchronous multi-channel mode as described above with respect to FIG.5, FIG. 6, FIG. 7, FIG. 8A, and FIG. 8B. In an embodiment, thecommunication device 900 is utilized in the AP 114 or the client station154. In an embodiment, the communication device 900 is configured toselectively transmit and/or receive signals described above withreference to FIGS. 5-7. In an embodiment, the communication device 900is further configured for selective DBC operation as described abovewith reference to FIG. 3.

The communication device 900 is similar to the communication device 400as described above with respect to FIG. 4A, and like-numbered elementsnot described in detail for purpose of brevity. The communication device900 includes a packet forwarding processor 904 configured to forwardpackets among the two communication channels and a WAN connection (notshown). The communication device 900 also includes a master MACprocessor 908 (MAC-M), a second MAC processor 912 (MAC-2), a first PHYprocessor 916, and a second PHY processor 920. The master MAC processor908 is coupled to both the first PHY processor 916 and the second PHYprocessor 920. The second MAC processor 912 is coupled to the second PHYprocessor 920. The master MAC processor 908 exchanges frame data withthe first PHY processor 916, and the second MAC processor 912 exchangesframe data with the second PHY processor 920. In the multi-channelmodes, the master MAC processor 908 also exchanges frame data with thefirst PHY processor 916 while the second MAC processor 912 is idle.

In an embodiment, master MAC processor 908 and the second MAC processor912 correspond to the MAC processor 126 of FIG. 1. In anotherembodiment, the master MAC processor 908 and the second MAC processor912 correspond to the MAC processor 166 of FIG. 1. In an embodiment, thefirst PHY processor 916 and the second PHY processor 920 correspond tothe PHY processor 130 of FIG. 1. In another embodiment, the first PHYprocessor 916 and the second PHY processor 920 correspond to the PHYprocessor 170 of FIG. 1.

The communication device 900 also includes synchronization controlcircuitry 932.

In the multi-channel modes, the forwarding processor 904 exchanges dataonly with the master MAC processor 908; and the master MAC processor908, the first PHY processor 916, the second PHY processor 920, and thesynchronization control circuitry 932 operate in a manner similar tocommunication device 400 of FIG. 4A. Also in the multi-channel modes,the second PHY processor 920 exchanges frame data with the master MACprocessor 908 while the second MAC processor 912 is idle.

On the other hand, in the DBC mode, the forwarding processor 904exchanges data with both the master MAC processor 908 and the second MACprocessor 912; and the master MAC processor 908, the second MACprocessor 912, the first PHY processor 916, and the second PHY processor920, operate in a manner similar to communication device 300 of FIG. 3.Also in the DBC mode, the synchronization control circuitry 932 is idle.

The communication device 900 is configured to selectively switch betweenthe multi-channel modes and the DBC mode. In an embodiment, the choiceof a particular mode of operation is determined based on the volume oftraffic and/or a number of client station 154 being serviced by the AP114. In an embodiment, if a large number of client stations 154 that canoperate on both the first communication channel and the secondcommunication channel are present in the WLAN 110, DBC operation ispreferred. In an embodiment, if a large number of client stations 154are present on a single communication channel, multi-channel operationis preferred. In an embodiment, the AP 114 may prefer multi-channeloperation when the AP 114 is servicing a small number of client station154 with a high throughput.

FIG. 10 is a flow diagram of an example method 1000 for wireless localarea network (WLAN) communication by a first WLAN communication device,according to an embodiment. In some embodiments, the AP 114 of FIG. 1 isconfigured to implement the method 1000 (in other words, the AP 114 isthe first WLAN communication device). In an embodiment, the method 1000is implemented by the AP 114 by utilizing the communication device 400,the communication device 450, or the communication device 900 asdescribed above with reference to FIGS. 4A-B and 9. The method 1000 isdescribed, however, in the context of the AP 114 merely for explanatorypurposes and, in other embodiments, the method 1000 is implemented byanother suitable device such as the client station 154. In variousembodiments, the method 1000 is utilized to generate signalscorresponding to those described above in reference to FIGS. 5-7. Invarious embodiments, the method 1000 is utilized with channelizationssuch as described above in reference to FIGS. 8A-B.

At block 1004, the AP 114 generates a first media access control (MAC)data unit. In an embodiment, the MAC data unit is an MPDU, A-MPDU,MMPDU, or other suitable MAC data unit. In an embodiment, the first MACdata unit corresponds to the PHY data portion 624 (FIG. 6) and includes,for example, an MPDU intended for a client station 154. In anotherembodiment, the first MAC data unit corresponds to the PHY data portion724-1, 724-2, or 724-3 (FIG. 7).

At block 1008, the AP 114 transmits the first MAC data unit to a secondWLAN communication device via a first WLAN communication channel havinga first radio frequency (RF) bandwidth. In an embodiment, the secondWLAN communication is the client station 154 to which the first MAC dataunit is transmitted. In an embodiment, the first WLAN communicationchannel corresponds to the communication channel 608. In anotherembodiment, the communication channel corresponds to the communicationchannel 708. In an embodiment, the first RF bandwidth is a bandwidthwithin the 5 GHz band, the 6 GHz band, or other suitable band.

At block 1012, the AP 114 receives a second MAC data unit from thesecond WLAN communication device via a second WLAN communication channelhaving a second RF bandwidth that does not overlap the first RFbandwidth, where the second MAC data unit corresponds to anacknowledgment of the first MAC data unit from the second WLANcommunication device. In an embodiment, for example, the AP 114 receivesthe acknowledgment 644 via the second communication channel 616 (FIG.6). In another embodiment, the AP 114 receives the acknowledgment 764-1,764-2, or 764-3 via the second communication channel 716.

In an embodiment, generating the first MAC data unit includes providing,by a single MAC layer processor implemented on one or more integratedcircuit (IC) devices of the first WLAN communication device, the firstMAC data unit to one or more baseband signal processors of the firstWLAN communication device, wherein the one or more baseband signalprocessors are implemented on the one or more IC devices, andgenerating, at the one or more baseband signal processors, a firstbaseband signal that corresponds to the first MAC data unit. In anembodiment, for example, the single MAC layer processor corresponds tothe MAC processor 408 (FIG. 4A), MAC processor 458 (FIG. 4B), or MACprocessor 908 (FIG. 9) and the first baseband signal processorcorresponds to the baseband processor 424 or 432 (FIG. 4A), the basebandprocessor 474 (FIG. 4B), or the baseband processor 924 or 928 (FIG. 9).

In an embodiment, transmitting the first MAC data unit comprisestransmitting, by a first RF radio of a plurality of RF radios of thefirst WLAN communication device and to the second WLAN communicationdevice via the first WLAN communication channel, a first RF signal thatcorresponds to the first baseband signal and occupies the first RFbandwidth. In an embodiment, for example, the RF radio 428 transmits thefirst RF signal 620 (FIG. 6) or the first RF signal 720 (FIG. 7).

In some embodiments, receiving the second MAC data unit includesreceiving, at a second RF radio of the plurality of RF radios and fromthe second WLAN communication device via the second WLAN communicationchannel, a second RF signal that corresponds to the second MAC data unitand occupies the second RF bandwidth. In some such embodiments, themethod 1000 further includes generating, by the one or more basebandsignal processors, a second baseband signal that corresponds to thesecond MAC data unit, and generating, by the one or more baseband signalprocessors, the second MAC data unit using the second baseband signal.In an embodiment, for example, the AP 114 receives the RF signal 640 atthe RF radio 436.

In an embodiment, the method 1000 further includes: providing, by thesingle MAC layer processor, a third MAC data unit to the one or morebaseband signal processors; generating, at the one or more basebandsignal processors, a third baseband signal that corresponds to the thirdMAC data unit; and transmitting, by the first RF radio and to the secondWLAN communication device via the first WLAN communication channel, athird RF signal that corresponds to the third baseband signal. In anembodiment, the first RF radio transmits at least a portion of the thirdRF signal simultaneously with reception by the second RF radio of atleast a portion of the second RF signal. In an embodiment, the third MACdata unit corresponds to the PHY data portion 664 and the third RFsignal corresponds to the RF signal 660.

In an embodiment, the first WLAN communication channel includes aprimary channel and the method 1000 further includes: providing, by thesingle MAC layer processor, a third MAC data unit to the one or morebaseband signal processors; generating, at the one or more basebandsignal processors, a third baseband signal that corresponds to the thirdMAC data unit; transmitting, by the first RF radio and to a legacy WLANcommunication device via the first WLAN communication channel, a thirdRF signal that corresponds to the third baseband signal; receiving, atthe first RF radio and from the legacy WLAN communication device via thefirst WLAN communication channel, a fourth RF signal that corresponds toan acknowledgment of the third MAC data unit; generating, by the one ormore baseband signal processors, a fourth baseband signal thatcorresponds to the acknowledgment of the third MAC data unit; andgenerating, by the one or more baseband signal processors, a fourth MACdata unit that corresponds to the acknowledgment of the third MAC dataunit. In an embodiment, for example, the primary channel corresponds tothe primary channel 812 and the AP 114 generates and transmits a MACdata unit to a legacy WLAN communication device, as described above withrespect to FIG. 8A.

In some embodiments, the first RF bandwidth and first WLAN communicationchannel are designated for MAC data units that include forward traffic,and the second RF bandwidth and the second WLAN communication channelare designated for MAC data units that include reverse traffic thatacknowledges the forward traffic. In an embodiment, the forward trafficincludes multi-user, multiple input multiple output (MU-MIMO) forwardtraffic transmitted to a plurality of WLAN communication device thatincludes the second WLAN communication devices, and the reverse trafficis triggered by a trigger MAC data unit transmitted via the second WLANcommunication channel to the plurality of WLAN communication devices. Inan embodiment, the forward traffic includes orthogonal frequencydivision multiple access (OFDMA) forward traffic to a plurality of WLANcommunication devices that includes the second WLAN communicationdevice, and the reverse traffic is triggered by a trigger MAC data unittransmitted via the second WLAN communication channel to the pluralityof WLAN communication devices.

In some embodiments, the first RF bandwidth and first WLAN communicationchannel are designated for MAC data units that include downlink traffictransmitted from the first WLAN communication device, wherein the firstWLAN communication device is a WLAN access point, and the second RFbandwidth and the second WLAN communication channel are designated forMAC data units that include uplink traffic transmitted to the WLANaccess point. In one such embodiment, the downlink traffic includesMU-MIMO traffic to a plurality of WLAN communication devices thatincludes the second WLAN communication device, and the uplink traffic istriggered by a trigger MAC data unit transmitted via the second WLANcommunication channel to the plurality of WLAN communication devices. Inanother such embodiment, the downlink traffic includes OFDMA data unitstransmitted to a plurality of WLAN communication devices that includesthe second WLAN communication device, and the uplink traffic includesOFDMA data units that are transmitted by the plurality of WLANcommunication devices and triggered by a trigger MAC data unittransmitted via the second WLAN communication channel to the pluralityof WLAN communication devices.

In an embodiment, the first and second RF bandwidths have differentrespective bandwidths and one of the first and second RF bandwidths islarger than another of the first and second RF bandwidths. In anembodiment, for example, the respective first and second RF bandwidthsare 80 MHz and 20 MHz, 160 MHz and 20 MHz, 320 MHz and 40 MHz, or othersuitable bandwidths, as described above with respect to FIG. 5 and FIG.6.

In an embodiment, the first RF bandwidth and the second RF bandwidth areseparated by at least 160 MHz.

FIG. 11 is a flow diagram of an example method 1100 for wireless localarea network (WLAN) communication by a first WLAN communication device,according to an embodiment. In some embodiments, the client station 154of FIG. 1 is configured to implement the method 1100. In an embodiment,the method 1100 is implemented by the client station 154 by utilizingthe communication device 400, the communication device 450, or thecommunication device 900 as described above with reference to FIGS. 4A-Band 9. The method 1100 is described, however, in the context of theclient station 154 merely for explanatory purposes and, in otherembodiments, the method 1100 is implemented by another suitable devicesuch as the AP 114. In various embodiments, the method 1100 is utilizedto receive and process signals corresponding to those described above inreference to FIGS. 5-7. In various embodiments, the method 1100 isutilized with channelizations such as described above in reference toFIGS. 8A-B.

At block 1104, the client station 154 (as a first WLAN communicationdevice) receives a first MAC data unit from a second WLAN communicationdevice via a first WLAN communication channel having a first radiofrequency (RF) bandwidth. In an embodiment, the MAC data unit is anMPDU, A-MPDU, MMPDU, or other suitable MAC data unit. In an embodiment,the first MAC data unit corresponds to the PHY data portion 624 (FIG. 6)and includes, for example, an MPDU intended for the client station 154.In another embodiment, the first MAC data unit corresponds to the PHYdata portion 724-1, 724-2, or 724-3 (FIG. 7).

At block 1108, the client station 154 generates a second MAC data unitconfigured to acknowledge the first MAC data unit. In an embodiment, forexample, the client station generates the acknowledgment 644. In anotherembodiment, the client station 154 generates the acknowledgment 764-1,764-2, or 764-3.

At block 1112, the client station 154 transmits the second MAC data unitto the second WLAN communication device via a second WLAN communicationchannel having a second RF bandwidth that does not overlap the first RFbandwidth. In an embodiment, for example, the client station 154transmits the acknowledgment 644 as the RF signal 640.

In an embodiment, receiving the first MAC data unit includes receiving,at a first RF radio of a plurality of RF radios of the first WLANcommunication device and from the second WLAN communication device viathe first WLAN communication channel, a first RF signal that correspondsto the first MAC data unit and occupies the first RF bandwidth,generating, by one or more baseband signal processors implemented on oneor more integrated circuit (IC) devices of the first WLAN communicationdevice, a first baseband signal that corresponds to the first MAC dataunit, and generating, by the one or more baseband signal processors, thefirst MAC data unit using the first baseband signal. In an embodiment,the first RF radio corresponds to the RF radio 428 and receives the RFsignal 620 from the AP 114.

In an embodiment, generating the second MAC data unit includesproviding, by a single MAC layer processor implemented on the one ormore IC devices, the second MAC data unit to the one or more basebandsignal processors, and generating, at the one or more baseband signalprocessors, a second baseband signal that corresponds to the second MACdata unit. In an embodiment, for example, the MAC layer processor is theMAC processor 408 or 474 and the baseband signal processor is thebaseband processor 424 or 432 (FIG. 4A or 4B).

In an embodiment, transmitting the second MAC data unit includestransmitting, by a second RF radio of the plurality of RF radios and tothe second WLAN communication device via the second WLAN communicationchannel, a second RF signal that corresponds to the second basebandsignal and occupies the second RF bandwidth. In an embodiment, thesecond RF radio is the RF radio 436 that transmits the RF signal 640.

In an embodiment, the method 1100 further includes providing, by thesingle MAC layer processor, a third MAC data unit to the one or morebaseband signal processors; generating, at the one or more basebandsignal processors, a third baseband signal that corresponds to the thirdMAC data unit; and transmitting, by the second RF radio and to thesecond WLAN communication device via the first WLAN communicationchannel, a third RF signal that corresponds to the third basebandsignal; wherein the second RF radio transmits at least a portion of thethird RF signal simultaneously with reception by the first RF radio ofat least a portion of the first RF signal. In an embodiment, forexample, the client station 154 receives the RF signal 660 andsimultaneously transmits the RF signal 640.

In an embodiment, the first WLAN communication channel includes aprimary channel, the method 1100 further including: providing, by thesingle MAC layer processor, a third MAC data unit to the one or morebaseband signal processors; generating, at the one or more basebandsignal processors, a third baseband signal that corresponds to the thirdMAC data unit; transmitting, by the first RF radio and to a legacy WLANcommunication device via the first WLAN communication channel, a thirdRF signal that corresponds to the third baseband signal; receiving, atthe first RF radio and from the legacy WLAN communication device via thefirst WLAN communication channel, a fourth RF signal that corresponds toan acknowledgment of the third MAC data unit; generating, by the one ormore baseband signal processors, a fourth baseband signal thatcorresponds to the acknowledgment of the third MAC data unit;generating, by the one or more baseband signal processors, a fourth MACdata unit that corresponds to the acknowledgment of the third MAC dataunit.

In an embodiment, the first RF bandwidth and first WLAN communicationchannel are designated for MAC data units that include forward traffic,and the second RF bandwidth and the second WLAN communication channelare designated for MAC data units that include reverse traffic thatacknowledges the forward traffic.

In an embodiment, the forward traffic includes multi-user, multipleinput multiple output (MU-MIMO) forward traffic transmitted to aplurality of WLAN communication device that includes the second WLANcommunication devices, the reverse traffic is triggered by a trigger MACdata unit transmitted via the second WLAN communication channel to theplurality of WLAN communication devices.

In an embodiment, the forward traffic includes orthogonal frequencydivision multiple access (OFDMA) forward traffic to a plurality of WLANcommunication devices that includes the second WLAN communicationdevice, and the reverse traffic is triggered by a trigger MAC data unittransmitted via the second WLAN communication channel to the pluralityof WLAN communication devices.

In an embodiment, the first RF bandwidth and first WLAN communicationchannel are designated for MAC data units that include downlink traffictransmitted to the first WLAN communication device, wherein the firstWLAN communication device is a WLAN client station. In an embodiment,the second RF bandwidth and the second WLAN communication channel aredesignated for MAC data units that include uplink traffic transmittedfrom the WLAN client station.

In an embodiment, the downlink traffic includes MU-MIMO traffic to aplurality of WLAN communication devices that includes the first WLANcommunication device, and the uplink traffic is triggered by a triggerMAC data unit transmitted via the second WLAN communication channel tothe plurality of WLAN communication devices.

In an embodiment, the downlink traffic includes OFDMA data unitstransmitted to a plurality of WLAN communication devices that includesthe first WLAN communication device, and the uplink traffic includesOFDMA data units that are transmitted by the plurality of WLANcommunication devices and triggered by a trigger MAC data unittransmitted via the second WLAN communication channel to the pluralityof WLAN communication devices.

In an embodiment, the first and second RF bandwidths have differentrespective bandwidths and one of the first and second RF bandwidths islarger than another of the first and second RF bandwidths.

In an embodiment, the first RF bandwidth and the second RF bandwidth areseparated by at least 160 MHz.

Embodiment 1: A method for wireless local area network (WLAN)communication by a first WLAN communication device, the methodcomprising: generating, at the first WLAN communication device, a firstmedia access control (MAC) data unit; transmitting, from the first WLANcommunication device, the first MAC data unit to a second WLANcommunication device via a first WLAN communication channel having afirst radio frequency (RF) bandwidth; receiving, at the first WLANcommunication device, a second MAC data unit from the second WLANcommunication device via a second WLAN communication channel having asecond RF bandwidth that does not overlap the first RF bandwidth,wherein the second MAC data unit corresponds to an acknowledgment of thefirst MAC data unit from the second WLAN communication device.

Embodiment 2: The method of embodiment 1, wherein: generating the firstMAC data unit comprises providing, by a single MAC layer processorimplemented on one or more integrated circuit (IC) devices of the firstWLAN communication device, the first MAC data unit to one or morebaseband signal processors of the first WLAN communication device,wherein the one or more baseband signal processors are implemented onthe one or more IC devices, and generating, at the one or more basebandsignal processors, a first baseband signal that corresponds to the firstMAC data unit; transmitting the first MAC data unit comprisestransmitting, by a first RF radio of a plurality of RF radios of thefirst WLAN communication device, to the second WLAN communication devicevia the first WLAN communication channel, a first RF signal thatcorresponds to the first baseband signal and occupies the first RFbandwidth; receiving the second MAC data unit comprises receiving, at asecond RF radio of the plurality of RF radios and from the second WLANcommunication device via the second WLAN communication channel, a secondRF signal that corresponds to the second MAC data unit and occupies thesecond RF bandwidth, generating, by the one or more baseband signalprocessors, a second baseband signal that corresponds to the second MACdata unit, and generating, by the one or more baseband signalprocessors, the second MAC data unit using the second baseband signal.

Embodiment 3. The method of embodiment 2, further comprising: providing,by the single MAC layer processor, a third MAC data unit to the one ormore baseband signal processors; generating, at the one or more basebandsignal processors, a third baseband signal that corresponds to the thirdMAC data unit; transmitting, by the first RF radio and to the secondWLAN communication device via the first WLAN communication channel, athird RF signal that corresponds to the third baseband signal; whereinthe first RF radio transmits at least a portion of the third RF signalsimultaneously with reception by the second RF radio of at least aportion of the second RF signal.

Embodiment 4. The method of embodiment 2, wherein the first WLANcommunication channel includes a primary channel, the method furtherincluding: providing, by the single MAC layer processor, a third MACdata unit to the one or more baseband signal processors; generating, atthe one or more baseband signal processors, a third baseband signal thatcorresponds to the third MAC data unit; transmitting, by the first RFradio and to a legacy WLAN communication device via the first WLANcommunication channel, a third RF signal that corresponds to the thirdbaseband signal; receiving, at the first RF radio and from the legacyWLAN communication device via the first WLAN communication channel, afourth RF signal that corresponds to an acknowledgment of the third MACdata unit; generating, by the one or more baseband signal processors, afourth baseband signal that corresponds to the acknowledgment of thethird MAC data unit; generating, by the one or more baseband signalprocessors, a fourth MAC data unit that corresponds to theacknowledgment of the third MAC data unit.

Embodiment 5. The method of embodiment 1, wherein: the first RFbandwidth and first WLAN communication channel are designated for MACdata units that include forward traffic; the second RF bandwidth and thesecond WLAN communication channel are designated for MAC data units thatinclude reverse traffic that acknowledges the forward traffic.

Embodiment 6. The method of embodiment 5, wherein: the forward trafficincludes multi-user, multiple input multiple output (MU-MIMO) forwardtraffic transmitted to a plurality of WLAN communication device thatincludes the second WLAN communication devices; and the reverse trafficis triggered by a trigger MAC data unit transmitted via the second WLANcommunication channel to the plurality of WLAN communication devices.

Embodiment 7. The method of embodiment 5, wherein: the forward trafficincludes orthogonal frequency division multiple access (OFDMA) forwardtraffic to a plurality of WLAN communication devices that includes thesecond WLAN communication device; and

the reverse traffic is triggered by a trigger MAC data unit transmittedvia the second WLAN communication channel to the plurality of WLANcommunication devices.

Embodiment 8. The method of embodiment 1, wherein: the first RFbandwidth and first WLAN communication channel are designated for MACdata units that include downlink traffic transmitted from the first WLANcommunication device, wherein the first WLAN communication device is aWLAN access point; the second RF bandwidth and the second WLANcommunication channel are designated for MAC data units that includeuplink traffic transmitted to the WLAN access point.

Embodiment 9. The method of embodiment 8, wherein: the downlink trafficincludes MU-MIMO traffic to a plurality of WLAN communication devicesthat includes the second WLAN communication device; and the uplinktraffic is triggered by a trigger MAC data unit transmitted via thesecond WLAN communication channel to the plurality of WLAN communicationdevices.

Embodiment 10. The method of embodiment 8, wherein: the downlink trafficincludes OFDMA data units transmitted to a plurality of WLANcommunication devices that includes the second WLAN communicationdevice; and the uplink traffic includes OFDMA data units that aretransmitted by the plurality of WLAN communication devices and triggeredby a trigger MAC data unit transmitted via the second WLAN communicationchannel to the plurality of WLAN communication devices.

Embodiment 11. The method of embodiment 1, wherein the first and secondRF bandwidths have different respective bandwidths and one of the firstand second RF bandwidths is larger than another of the first and secondRF bandwidths.

Embodiment 12. The method of embodiment 1, wherein the first RFbandwidth and the second RF bandwidth are separated by at least 160 MHz.

Embodiment 13. A method for wireless local area network (WLAN)communication by a first WLAN communication device, the methodcomprising: receiving, at the first WLAN communication device, a firstmedia access control (MAC) data unit from a second WLAN communicationdevice via a first WLAN communication channel having a first radiofrequency (RF) bandwidth; generating, at the first WLAN communicationdevice, a second MAC data unit configured to acknowledge the first MACdata unit; transmitting, by the first WLAN communication device, thesecond MAC data unit to the second WLAN communication device via asecond WLAN communication channel having a second RF bandwidth that doesnot overlap the first RF bandwidth.

Embodiment 14. The method of embodiment 13, wherein: receiving the firstMAC data unit comprises receiving, at a first RF radio of a plurality ofRF radios of the first WLAN communication device and from the secondWLAN communication device via the first WLAN communication channel, afirst RF signal that corresponds to the first MAC data unit and occupiesthe first RF bandwidth, generating, by one or more baseband signalprocessors implemented on one or more integrated circuit (IC) devices ofthe first WLAN communication device, a first baseband signal thatcorresponds to the first MAC data unit, and generating, by the one ormore baseband signal processors, the first MAC data unit using the firstbaseband signal; generating the second MAC data unit comprisesproviding, by a single MAC layer processor implemented on the one ormore IC devices, the second MAC data unit to the one or more basebandsignal processors, and generating, at the one or more baseband signalprocessors, a second baseband signal that corresponds to the second MACdata unit; transmitting the second MAC data unit comprises transmitting,by a second RF radio of the plurality of RF radios and to the secondWLAN communication device via the second WLAN communication channel, asecond RF signal that corresponds to the second baseband signal andoccupies the second RF bandwidth.

Embodiment 15. The method of embodiment 14, further comprising:providing, by the single MAC layer processor, a third MAC data unit tothe one or more baseband signal processors; generating, at the one ormore baseband signal processors, a third baseband signal thatcorresponds to the third MAC data unit; transmitting, by the second RFradio and to the second WLAN communication device via the first WLANcommunication channel, a third RF signal that corresponds to the thirdbaseband signal; wherein the second RF radio transmits at least aportion of the third RF signal simultaneously with reception by thefirst RF radio of at least a portion of the first RF signal.

Embodiment 16. The method of embodiment 14, wherein the first WLANcommunication channel includes a primary channel, the method furtherincluding:

providing, by the single MAC layer processor, a third MAC data unit tothe one or more baseband signal processors; generating, at the one ormore baseband signal processors, a third baseband signal thatcorresponds to the third MAC data unit; transmitting, by the first RFradio and to a legacy WLAN communication device via the first WLANcommunication channel, a third RF signal that corresponds to the thirdbaseband signal; receiving, at the first RF radio and from the legacyWLAN communication device via the first WLAN communication channel, afourth RF signal that corresponds to an acknowledgment of the third MACdata unit; generating, by the one or more baseband signal processors, afourth baseband signal that corresponds to the acknowledgment of thethird MAC data unit; generating, by the one or more baseband signalprocessors, a fourth MAC data unit that corresponds to theacknowledgment of the third MAC data unit.

Embodiment 17. The method of embodiment 13, wherein: the first RFbandwidth and first WLAN communication channel are designated for MACdata units that include forward traffic; the second RF bandwidth and thesecond WLAN communication channel are designated for MAC data units thatinclude reverse traffic that acknowledges the forward traffic.

Embodiment 18. The method of embodiment 17, wherein: the forward trafficincludes multi-user, multiple input multiple output (MU-MIMO) forwardtraffic transmitted to a plurality of WLAN communication device thatincludes the second WLAN communication devices; and the reverse trafficis triggered by a trigger MAC data unit transmitted via the second WLANcommunication channel to the plurality of WLAN communication devices.

Embodiment 19. The method of embodiment 17, wherein: the forward trafficincludes orthogonal frequency division multiple access (OFDMA) forwardtraffic to a plurality of WLAN communication devices that includes thesecond WLAN communication device; and

the reverse traffic is triggered by a trigger MAC data unit transmittedvia the second WLAN communication channel to the plurality of WLANcommunication devices.

Embodiment 20. The method of embodiment 14, wherein: the first RFbandwidth and first WLAN communication channel are designated for MACdata units that include downlink traffic transmitted to the first WLANcommunication device, wherein the first WLAN communication device is aWLAN client station; the second RF bandwidth and the second WLANcommunication channel are designated for MAC data units that includeuplink traffic transmitted from the WLAN client station.

Embodiment 21. The method of embodiment 20, wherein: the downlinktraffic includes MU-MIMO traffic to a plurality of WLAN communicationdevices that includes the first WLAN communication device; and theuplink traffic is triggered by a trigger MAC data unit transmitted viathe second WLAN communication channel to the plurality of WLANcommunication devices.

Embodiment 22. The method of embodiment 20, wherein: the downlinktraffic includes OFDMA data units transmitted to a plurality of WLANcommunication devices that includes the first WLAN communication device;and the uplink traffic includes OFDMA data units that are transmitted bythe plurality of WLAN communication devices and triggered by a triggerMAC data unit transmitted via the second WLAN communication channel tothe plurality of WLAN communication devices.

Embodiment 23. The method of embodiment 13, wherein the first and secondRF bandwidths have different respective bandwidths and one of the firstand second RF bandwidths is larger than another of the first and secondRF bandwidths.

Embodiment 24. The method of embodiment 13, wherein the first RFbandwidth and the second RF bandwidth are separated by at least 160 MHz.

At least some of the various blocks, operations, and techniquesdescribed above may be implemented utilizing hardware, a processorexecuting firmware instructions, a processor executing softwareinstructions, or any combination thereof. When implemented utilizing aprocessor executing software or firmware instructions, the software orfirmware instructions may be stored in any computer readable memory suchas on a magnetic disk, an optical disk, or other storage medium, in aRAM or ROM or flash memory, processor, hard disk drive, optical diskdrive, tape drive, etc. The software or firmware instructions mayinclude machine readable instructions that, when executed by one or moreprocessors, cause the one or more processors to perform various acts.

When implemented in hardware, the hardware may comprise one or more ofdiscrete components, an integrated circuit, an application-specificintegrated circuit (ASIC), a programmable logic device (PLD), etc.

While the present invention has been described with reference tospecific examples, which are intended to be illustrative only and not tobe limiting of the invention, changes, additions and/or deletions may bemade to the disclosed embodiments without departing from the scope ofthe invention.

What is claimed is:
 1. A method for wireless local area network (WLAN)communication by a first WLAN communication device, the methodcomprising: generating, at the first WLAN communication device, aplurality of first media access control (MAC) data units intended for aplurality of second WLAN communication devices; transmitting, from thefirst WLAN communication device, the plurality of first MAC data unitsto the plurality of second WLAN communication devices via a first WLANcommunication channel having a first radio frequency (RF) bandwidth, theplurality of first MAC data units simultaneously transmitted as part ofa first multi-user transmission; generating, at the first WLANcommunication device, a second MAC data unit having a trigger frameconfigured to prompt a second multi-user transmission by the pluralityof second WLAN communication devices that includes acknowledgmentinformation regarding the plurality of first MAC data units;transmitting, from the first WLAN communication device, the second MACdata unit to the plurality of second WLAN communication devices via asecond WLAN communication channel having a second RF bandwidth that doesnot overlap the first RF bandwidth; and receiving, at the first WLANcommunication device, a second multi-user transmission from theplurality of second communication devices via the second WLANcommunication channel, the second multi-user transmission including i)the acknowledgment information regarding the plurality of first MAC dataunits, and ii) simultaneous transmissions from the plurality of secondWLAN communication devices within the second WLAN communication channel.2. The method of claim 1, wherein: generating the first MAC data unitcomprises providing, by a single MAC layer processor implemented on oneor more integrated circuit (IC) devices of the first WLAN communicationdevice, the first MAC data unit to one or more baseband signalprocessors of the first WLAN communication device, wherein the one ormore baseband signal processors are implemented on the one or more ICdevices, and generating, at the one or more baseband signal processors,a first baseband signal that corresponds to the first MAC data unit;transmitting the first MAC data unit comprises transmitting, by a firstRF radio of a plurality of RF radios of the first WLAN communicationdevice, to the second WLAN communication device via the first WLANcommunication channel, a first RF signal that corresponds to the firstbaseband signal and occupies the first RF bandwidth; receiving thesecond MAC data unit comprises receiving, at a second RF radio of theplurality of RF radios and from the second WLAN communication device viathe second WLAN communication channel, a second RF signal thatcorresponds to the second MAC data unit and occupies the second RFbandwidth, generating, by the one or more baseband signal processors, asecond baseband signal that corresponds to the second MAC data unit, andgenerating, by the one or more baseband signal processors, the secondMAC data unit using the second baseband signal.
 3. The method of claim2, further comprising: providing, by the single MAC layer processor, athird MAC data unit to the one or more baseband signal processors;generating, at the one or more baseband signal processors, a thirdbaseband signal that corresponds to the third MAC data unit;transmitting, by the first RF radio and to the second WLAN communicationdevice via the first WLAN communication channel, a third RF signal thatcorresponds to the third baseband signal; wherein the first RF radiotransmits at least a portion of the third RF signal simultaneously withreception by the second RF radio of at least a portion of the second RFsignal.
 4. The method of claim 2, wherein the first WLAN communicationchannel includes a primary channel, the method further including:providing, by the single MAC layer processor, a third MAC data unit tothe one or more baseband signal processors; generating, at the one ormore baseband signal processors, a third baseband signal thatcorresponds to the third MAC data unit; transmitting, by the first RFradio and to a legacy WLAN communication device via the first WLANcommunication channel, a third RF signal that corresponds to the thirdbaseband signal; receiving, at the first RF radio and from the legacyWLAN communication device via the first WLAN communication channel, afourth RF signal that corresponds to an acknowledgment of the third MACdata unit; generating, by the one or more baseband signal processors, afourth baseband signal that corresponds to the acknowledgment of thethird MAC data unit; generating, by the one or more baseband signalprocessors, a fourth MAC data unit that corresponds to theacknowledgment of the third MAC data unit.
 5. The method of claim 1,wherein: the first RF bandwidth and first WLAN communication channel aredesignated for MAC data units that include forward traffic; the secondRF bandwidth and the second WLAN communication channel are designatedfor MAC data units that include reverse traffic that acknowledges theforward traffic.
 6. The method of claim 5, wherein: the first multi-usertransmission includes a first multi-user, multiple input multiple output(MU-MIMO) transmission transmitted to the plurality of second WLANcommunication devices; and the second multi-user transmission includes asecond MU-MIMO transmission from the plurality of second WLANcommunication devices.
 7. The method of claim 5, wherein: the firstmulti-user transmission includes a first orthogonal frequency divisionmultiple access (OFDMA) transmission to the plurality of second WLANcommunication devices; and the second multi-user transmission includes asecond OFDMA transmission from the plurality of second WLANcommunication devices.
 8. The method of claim 1, wherein: the first RFbandwidth and first WLAN communication channel are designated for MACdata units that include downlink traffic transmitted from the first WLANcommunication device, wherein the first WLAN communication device is aWLAN access point; the second RF bandwidth and the second WLANcommunication channel are designated for MAC data units that includeuplink traffic transmitted to the WLAN access point.
 9. The method ofclaim 8, wherein: the first multi-user transmission includes a downlinkmulti-user, multiple input multiple output (MU-MIMO) transmission to theplurality of second WLAN communication devices; and the secondmulti-user transmission includes an uplink MU-MIMO transmission from theplurality of second WLAN communication devices.
 10. The method of claim8, wherein: the first multi-user transmission includes a downlinkorthogonal frequency division multiple access (OFDMA) transmission tothe plurality of second WLAN communication devices; and the secondmulti-user transmission includes an uplink OFDMA transmission from theplurality of second WLAN communication devices.
 11. The method of claim1, wherein the first and second RF bandwidths have different respectivebandwidths and one of the first and second RF bandwidths is larger thananother of the first and second RF bandwidths.
 12. The method of claim1, wherein the first RF bandwidth and the second RF bandwidth areseparated by at least 160 MHz.
 13. A method for wireless local areanetwork (WLAN) communication by a first WLAN communication device, themethod comprising: receiving, at the first WLAN communication device, afirst multi-user transmission from a second WLAN communication devicevia a first WLAN communication channel having a first radio frequency(RF) bandwidth, the first multi-user transmission having data intendedfor a plurality of WLAN communication devices that includes the firstWLAN communication device, including a first media access control (MAC)data unit intended for the first WLAN communication device; generating,at the first WLAN communication device, a second MAC data unitconfigured to acknowledge the first MAC data unit; receiving, at thefirst WLAN communication device, a third MAC data unit transmitted bythe second WLAN communication device via a second WLAN communicationchannel having a second RF bandwidth that does not overlap the first RFbandwidth, the third MAC data unit configured to prompt the plurality ofWLAN communication devices to transmit to the second WLAN communicationdevice as part of a second multi-user transmission; and responsive tothe third MAC data unit, transmitting, by the first WLAN communicationdevice, the second MAC data unit as part of the second multi-usertransmission to the second WLAN communication device via the second WLANcommunication channel, wherein transmitting the second MAC data unit isperformed simultaneously with one or more transmissions by the one ormore other WLAN communication devices within the second WLANcommunication channel.
 14. The method of claim 13, wherein: receivingthe first MAC data unit comprises receiving, at a first RF radio of aplurality of RF radios of the first WLAN communication device and fromthe second WLAN communication device via the first WLAN communicationchannel, a first RF signal that corresponds to the first MAC data unitand occupies the first RF bandwidth, generating, by one or more basebandsignal processors implemented on one or more integrated circuit (IC)devices of the first WLAN communication device, a first baseband signalthat corresponds to the first MAC data unit, and generating, by the oneor more baseband signal processors, the first MAC data unit using thefirst baseband signal; generating the second MAC data unit comprisesproviding, by a single MAC layer processor implemented on the one ormore IC devices, the second MAC data unit to the one or more basebandsignal processors, and generating, at the one or more baseband signalprocessors, a second baseband signal that corresponds to the second MACdata unit; transmitting the second MAC data unit comprises transmitting,by a second RF radio of the plurality of RF radios and to the secondWLAN communication device via the second WLAN communication channel, asecond RF signal that corresponds to the second baseband signal andoccupies the second RF bandwidth.
 15. The method of claim 14, furthercomprising: providing, by the single MAC layer processor, a third MACdata unit to the one or more baseband signal processors; generating, atthe one or more baseband signal processors, a third baseband signal thatcorresponds to the third MAC data unit; transmitting, by the second RFradio and to the second WLAN communication device via the first WLANcommunication channel, a third RF signal that corresponds to the thirdbaseband signal; wherein the second RF radio transmits at least aportion of the third RF signal simultaneously with reception by thefirst RF radio of at least a portion of the first RF signal.
 16. Themethod of claim 14, wherein the first WLAN communication channelincludes a primary channel, the method further including: providing, bythe single MAC layer processor, a third MAC data unit to the one or morebaseband signal processors; generating, at the one or more basebandsignal processors, a third baseband signal that corresponds to the thirdMAC data unit; transmitting, by the first RF radio and to a legacy WLANcommunication device via the first WLAN communication channel, a thirdRF signal that corresponds to the third baseband signal; receiving, atthe first RF radio and from the legacy WLAN communication device via thefirst WLAN communication channel, a fourth RF signal that corresponds toan acknowledgment of the third MAC data unit; generating, by the one ormore baseband signal processors, a fourth baseband signal thatcorresponds to the acknowledgment of the third MAC data unit;generating, by the one or more baseband signal processors, a fourth MACdata unit that corresponds to the acknowledgment of the third MAC dataunit.
 17. The method of claim 13, wherein: the first RF bandwidth andfirst WLAN communication channel are designated for MAC data units thatinclude forward traffic; the second RF bandwidth and the second WLANcommunication channel are designated for MAC data units that includereverse traffic that acknowledges the forward traffic.
 18. The method ofclaim 17, wherein: the first multi-user transmission includes a firstmulti-user, multiple input multiple output (MU-MIMO) transmittedtransmission to the plurality of WLAN communication devices; and thesecond multi-user transmission includes a second MU-MIMO transmissionfrom the plurality of WLAN communication devices.
 19. The method ofclaim 17, wherein: the first multi-user transmission includes a firstorthogonal frequency division multiple access (OFDMA) transmission tothe plurality of WLAN communication devices; and the second multi-usertransmission includes a second MU-MIMO transmission from the pluralityof WLAN communication devices.
 20. The method of claim 13, wherein: thefirst RF bandwidth and first WLAN communication channel are designatedfor MAC data units that include downlink traffic transmitted to thefirst WLAN communication device, wherein the first WLAN communicationdevice is a WLAN client station; the second RF bandwidth and the secondWLAN communication channel are designated for MAC data units thatinclude uplink traffic transmitted from the WLAN client station.
 21. Themethod of claim 20, wherein: the first multi-user transmission includesa downlink multi-user, multiple input multiple output (MU-MIMO)transmission to the plurality of WLAN communication devices; and thesecond multi-user transmission includes an uplink MU-MIMO transmissionfrom the plurality of WLAN communication devices.
 22. The method ofclaim 20, wherein: the first multi-user transmission includes a downlinkorthogonal frequency division multiple access (OFDMA) transmission tothe plurality of WLAN communication devices; and the second multi-usertransmission includes an uplink OFDMA transmission from the plurality ofWLAN communication devices.
 23. The method of claim 13, wherein thefirst and second RF bandwidths have different respective bandwidths andone of the first and second RF bandwidths is larger than another of thefirst and second RF bandwidths.
 24. The method of claim 13, wherein thefirst RF bandwidth and the second RF bandwidth are separated by at least160 MHz.